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Hull JJ, Heu CC, Gross RJ, LeRoy DM, Schutze IX, Langhorst D, Fabrick JA, Brent CS. Doublesex is essential for masculinization but not feminization in Lygus hesperus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 166:104085. [PMID: 38307215 DOI: 10.1016/j.ibmb.2024.104085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/12/2024] [Accepted: 01/24/2024] [Indexed: 02/04/2024]
Abstract
In most holometabolous insects, sex differentiation occurs via a hierarchical cascade of transcription factors, with doublesex (dsx) regulating genes that control sex-specific traits. Although less is known in hemimetabolous insects, early evidence suggests that substantial differences exist from more evolutionarily advanced insects. Here, we identified and characterized dsx in Lygus hesperus (western tarnished plant bug), a hemipteran pest of many agricultural crops in western North America. The full-length transcript for L. hesperus dsx (Lhdsx) and several variants encode proteins with conserved DNA binding and oligomerization domains. Transcript profiling revealed that Lhdsx is ubiquitously expressed, likely undergoes alternative pre-mRNA splicing, and, unlike several model insects, is sex-biased rather than sex-specific. Embryonic RNA interference (RNAi) of Lhdsx only impacted sex development in adult males, which lacked both internal reproductive organs and external genitalia. No discernible impacts on adult female development or reproductivity were observed. RNAi knockdown of Lhdsx in nymphs likewise only affected adult males, which lacked the characteristic dimorphic coloration but had dramatically elevated vitellogenin transcripts. Gene knockout of Lhdsx by CRISPR/Cas9 editing yielded only females in G0 and strongly biased heterozygous G1 offspring to females with the few surviving males showing severely impaired genital development. These results indicate that L. hesperus male development requires Lhdsx, whereas female development proceeds via a basal pathway that functions independently of dsx. A fundamental understanding of sex differentiation in L. hesperus could be important for future gene-based management strategies of this important agricultural pest.
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Affiliation(s)
- J Joe Hull
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA.
| | - Chan C Heu
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Roni J Gross
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Dannialle M LeRoy
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Inana X Schutze
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Daniel Langhorst
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Jeffrey A Fabrick
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Colin S Brent
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
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Fukui T, Shoji K, Kiuchi T, Suzuki Y, Katsuma S. Masculinizer is not post-transcriptionally regulated by female-specific piRNAs during sex determination in the Asian corn borer, Ostrinia furnacalis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 156:103946. [PMID: 37075905 DOI: 10.1016/j.ibmb.2023.103946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/16/2023] [Indexed: 05/03/2023]
Abstract
Lepidopteran insects are heterogametic in females, although most insect species are heterogametic in males. In a lepidopteran model species, the silkworm Bombyx mori (Bombycoidea), the uppermost sex determinant Feminizer (Fem) has been identified on the female-specific W chromosome. Fem is a precursor of PIWI-interacting small RNA (piRNA). Fem piRNA forms a complex with Siwi, one of the two B. mori PIWI-clade Argonaute proteins. In female embryos, Fem piRNA-Siwi complex cleaves the mRNA of the male-determining gene Masculinizer (Masc), directing the female-determining pathway. In male embryos, Masc activates the male-determining pathway in the absence of Fem piRNA. Recently, W chromosome-derived piRNAs complementary to Masc mRNA have also been identified in the diamondback moth Plutella xylostella (Yponomeutoidea), indicating the convergent evolution of piRNA-dependent sex determination in Lepidoptera. Here, we show that this is not the case in the Asian corn borer, Ostrinia furnacalis (Pyraloidea). Although our previous studies demonstrated that O. furnacalis Masc (OfMasc) has a masculinizing function in the embryonic stage, the expression level of OfMasc was indistinguishable between the sexes at the timing of sex determination. Deep sequencing analysis identified no female-specific small RNAs mapped onto OfMasc mRNA. Embryonic knockdown of two PIWI genes did not affect the expression level of OfMasc in either sex. These results demonstrated that piRNA-dependent reduction of Masc mRNA in female embryos is not a common strategy of sex determination, which suggests the possibility of divergent evolution of sex determinants across the order Lepidoptera.
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Affiliation(s)
- Takahiro Fukui
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Keisuke Shoji
- Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Tomihara K, Katsuma S, Kiuchi T. Transcriptome analysis in the silkworm Bombyx mori overexpressing piRNA-resistant Masculinizer gene. Biochem Biophys Res Commun 2022; 616:104-109. [PMID: 35653824 DOI: 10.1016/j.bbrc.2022.05.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/21/2022] [Indexed: 11/02/2022]
Abstract
Dosage compensation is a process that produces a similar expression of sex-linked and autosomal genes. In the silkworm Bombyx mori with a WZ sex-determination system, the expression from the single Z in WZ females matches that of ZZ males due to the suppression of Z-linked genes in males. A primary maleness determinant gene, Masculinizer (Masc), is also required for dosage compensation. In females, silkworm Piwi is complexed with the W chromosome-derived female-specific Feminizer (Fem) PIWI-interacting RNA (piRNA) and cleaves Masc mRNA. When Fem piRNA-resistant Masc cDNA (Masc-R) is overexpressed in both sexes, only female larvae are dead during the larval stage. In this study, transcriptome analysis was performed in neonate larvae to examine the effects of Masc-R overexpression on a global gene expression profile. Z-linked genes were globally repressed in Masc-R-overexpressing females due to force-driven dosage compensation. In contrast, Masc-R overexpression had little effect on the expression of Z-linked genes and the male-specific isoform of B. mori insulin-like growth factor II mRNA-binding protein in males, indicating that excessive Masc expression strengthens neither dosage compensation nor maleness in males. Fourteen genes were differentially expressed between Masc-R-overexpressing and control neonate larvae in both sexes, suggesting Masc functions other than dosage compensation and masculinization.
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Affiliation(s)
- Kenta Tomihara
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Ranian K, Kashif Zahoor M, Zulhussnain M, Ahmad A. CRISPR/Cas9 mediated sex-ratio distortion by sex specific gene editing in Aedes aegypti. Saudi J Biol Sci 2022; 29:3015-3022. [PMID: 35531165 PMCID: PMC9073027 DOI: 10.1016/j.sjbs.2022.01.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/05/2022] [Accepted: 01/13/2022] [Indexed: 10/26/2022] Open
Abstract
Aedes aegypti is a principal vector for several viruses including dengue virus, chikungunya virus and zika virus. Economic burden of mosquito-borne diseases, relative failure of traditional control strategies and the resistance development against insecticides enforces towards genetic manipulation of Ae. aegypti. Hence, a key gene doublesex (Aedsx) which regulate sex differentiation and alternatively splices to form male and female specific transcripts (AedsxM and AedsxF ). CRISPR/Cas9 technique was employed to sex specifically disrupt the female-specific isoforms, AedsxF1 and AedsxF2 , both of which were shown to be expressed only in female mosquitoes. Targeting of dsxF at the developmental stage has resulted in various phenotypic anomalies of adult females. The rate of adult mutation phenotype was recorded between 29 and 37% along with anomalies of wing size, proboscis length and reduction in the sizes of pre-blood-meal and after blood-meal ovaries in dsxF1 and dsxF2 microinjected groups, respectively. These findings can be correlated with reduced fecundity rate of Go female, where AedsxF1 and AedsxF2 groups showed reduction rate in range of 23-31%. Furthermore, hatching inhibition rate of 28 to 36% was also observed in G1 generation when compared to the wildtype. Overall, these results demonstrated that AedsxF disruption has resulted in multiple female traits disruption including decreased fertility of the female that could directly or indirectly associated with reproduction and its disease transmitting abilities. All these findings suggesting that CRISPR works to alter the developmental pathways as predicted, and therefore this method potentially gives us the basis for the sex-ratio distortion system as genetic control approach for the management of this vector.
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Affiliation(s)
- Kanwal Ranian
- Department of Zoology, Government College University Faisalabad, Pakistan
| | | | | | - Aftab Ahmad
- Centre of Department of Biochemistry/US-Pakistan Center for Advance Studies in Agriculture and Food Security (USPCAS-AFS), University of Agriculture Faisalabad, Pakistan
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Wang Y, Rensink AH, Fricke U, Riddle MC, Trent C, van de Zande L, Verhulst EC. Doublesex regulates male-specific differentiation during distinct developmental time windows in a parasitoid wasp. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 142:103724. [PMID: 35093500 DOI: 10.1016/j.ibmb.2022.103724] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/19/2022] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
Sexually dimorphic traits in insects are subject to sexual selection, but our knowledge of the underlying molecular mechanisms is still scarce. Here we investigate how the highly conserved gene, Doublesex (Dsx), is involved in shaping sexual dimorphism in the model parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae). First, we present the revised Dsx gene structure including an alternative transcription start, and two additional male NvDsx transcript isoforms. We show sex-specific NvDsx expression and splicing throughout development, and demonstrate that transient NvDsx silencing in different male developmental stages shifts two sexually dimorphic traits from male to female morphology, with the effect being dependent on the timing of silencing. In addition, we determined the effect of NvDsx on the development of reproductive organs. Transient silencing of NvDsx in early male larvae affects the growth and differentiation of the internal and external reproductive tissues. We did not observe phenotypic changes in females after NvDsx silencing. Our results indicate that male NvDsx is required to suppress female-specific traits and/or to promote male-specific traits during distinct developmental windows. This provides new insights into the regulatory activity of Dsx during male wasp development in the Hymenoptera.
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Affiliation(s)
- Yidong Wang
- Wageningen University, Laboratory of Entomology, Wageningen, the Netherlands
| | - Anna H Rensink
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Ute Fricke
- Wageningen University, Laboratory of Entomology, Wageningen, the Netherlands
| | - Megan C Riddle
- Biology Department, Western Washington University, Washington, USA
| | - Carol Trent
- Biology Department, Western Washington University, Washington, USA
| | - Louis van de Zande
- Evolutionary Genetics, Development and Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Eveline C Verhulst
- Wageningen University, Laboratory of Entomology, Wageningen, the Netherlands; Wageningen University, Laboratory of Genetics, Wageningen, the Netherlands.
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Mine S, Sumitani M, Aoki F, Hatakeyama M, Suzuki MG. Effects of Functional Depletion of Doublesex on Male Development in the Sawfly, Athalia rosae. INSECTS 2021; 12:insects12100849. [PMID: 34680618 PMCID: PMC8538284 DOI: 10.3390/insects12100849] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 01/04/2023]
Abstract
Simple Summary The sawfly, Athalia rosae, exploits a haplodiploid mode of reproduction, in which fertilized eggs develop into diploid females, whereas unfertilized eggs parthenogenetically develop into haploid males. The doublesex (dsx) gene is a well-conserved transcription factor that regulates sexual differentiation in insects. In the present study, we knocked down the A. rosae ortholog of dsx (Ardsx) during several developmental stages with repeated double-stranded RNA (dsRNA) injections. As a result, knockdown of Ardsx in haploid males caused almost complete male-to-female sex reversal, but the resulting eggs were infertile. The same knockdown approach using diploid males caused complete male-to-female sex reversal; they were able to produce fertile eggs and exhibited female behaviors. The same RNAi treatment did not affect female differentiation. These results demonstrated that dsx in the sawfly is essential for male development and its depletion caused complete male-to-female sex reversal. This is the first demonstration of functional depletion of dsx not causing intersexuality but inducing total sex reversal in males instead. Abstract The doublesex (dsx) gene, which encodes a transcription factor, regulates sexual differentiation in insects. Sex-specific splicing of dsx occurs to yield male- and female-specific isoforms, which promote male and female development, respectively. Thus, functional disruption of dsx leads to an intersexual phenotype in both sexes. We previously identified a dsx ortholog in the sawfly, Athalia rosae. Similar to dsx in other insects, dsx in the sawfly yields different isoforms in males and females as a result of alternative splicing. The sawfly exploits a haplodiploid mode of reproduction, in which fertilized eggs develop into diploid females, whereas unfertilized eggs parthenogenetically develop into haploid males. In the present study, we knocked down the A. rosae ortholog of dsx (Ardsx) during several developmental stages with repeated double-stranded RNA (dsRNA) injections. Knockdown of Ardsx via parental RNA interference (RNAi), which enables knockdown of genes in offspring embryos, led to a lack of internal and external genitalia in haploid male progeny. Additional injection of dsRNA targeting Ardsx in these animals caused almost complete male-to-female sex reversal, but the resulting eggs were infertile. Notably, the same knockdown approach using diploid males obtained by sib-crossing caused complete male-to-female sex reversal; they were morphologically and behaviorally females. The same RNAi treatment did not affect female differentiation. These results indicate that dsx in the sawfly is essential for male development and its depletion caused complete male-to-female sex reversal. This is the first demonstration of functional depletion of dsx not causing intersexuality but inducing total sex reversal in males instead.
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Affiliation(s)
- Shotaro Mine
- Department of Biosciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan;
| | - Megumi Sumitani
- Division of Biotechnology, Institute of Agrobiological Sciences, NARO, Owashi, Tsukuba 305-8634, Japan;
| | - Fugaku Aoki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562, Japan;
| | - Masatsugu Hatakeyama
- Division of Applied Genetics, Institute of Agrobiological Sciences, NARO, Owashi, Tsukuba 305-8634, Japan;
| | - Masataka G. Suzuki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562, Japan;
- Correspondence: ; Tel.: +81-4-7136-3694
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7
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Kiuchi T, Katsuma S. Functional Characterization of Silkworm PIWI Proteins by Embryonic RNAi. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2021; 2360:19-31. [PMID: 34495504 DOI: 10.1007/978-1-0716-1633-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
The molecular mechanisms of sex-determination systems among insect orders and species are diverse. Therefore, genes involved in sex determination are strong candidates for insect pest management. Even though lepidopterans are major agricultural insect pests that cause widespread economic damage to various crops, their sex-determination systems have not been fully elucidated, even in the silkworm (Bombyx mori), a model lepidopteran insect. In 2014, we found that a female-specific W chromosome-derived PIWI-interacting RNA (piRNA) determines femaleness in silkworms. To analyze the function of two core silkworm piRNA biogenesis pathway genes, Siwi and BmAgo3, in the sex-determination system, we developed a genomic DNA and total RNA extraction strategy for a siRNA-injected single embryo. The siRNA-injected embryo can be molecularly sexed by W chromosome-specific DNA markers. Using complementary DNA (cDNA) reverse transcribed from the sexed RNA, we evaluated the knockdown effect of the PIWI protein-coding genes on a sexual development-related gene, Bombyx mori doublesex.
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Affiliation(s)
- Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Jin B, Zhao Y, Liu P, Sun Y, Li X, Zhang X, Chen XG, Gu J. The direct regulation of Aalbdsx on AalVgR is indispensable for ovarian development in Aedes albopictus. PEST MANAGEMENT SCIENCE 2021; 77:1654-1667. [PMID: 33205515 DOI: 10.1002/ps.6185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Aedes albopictus is an important vector with an extensive worldwide distribution. Only female mosquitoes play a significant role in the transmission of pathogens. Doublesex (dsx) is a central nexus gene in the insect somatic sex determination hierarchy. RESULTS In this study, we characterized the full-length sex-specific splicing forms of the Ae. albopictus dsx (Aalbdsx) gene. Then, we identified 15 direct target genes of DSX in adult females using digital gene expression combined with quantitative real-time polymerase chain reaction (qPCR) by performing a chromatin immunoprecipitation (ChIP) assay with specific DSX antibodies. Knockdown of Aalbdsx suppressed ovarian development and decreased the transcript levels of the Aalbdsx target vitellogenin receptor (VgR) gene, whereas vitellogenin (Vg) expression showed an increase in the fat body. Genes in the major Vg regulatory pathway were also up-regulated. CONCLUSION Our results suggest that both Vg and VgR are direct target genes of Aalbdsx and that direct regulation of Aalbdsx on VgR is indispensable for ovarian development in Ae. albopictus, which not only provides a reference for the further elucidation of the evolutionarily conserved role of dsx in Ae. albopictus sexual differentiation but also reveals potential molecular targets for application to the development of sterile male mosquitoes to be released for vector control. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Binbin Jin
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yijie Zhao
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Peiwen Liu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yan Sun
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Xiaocong Li
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Xin Zhang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Jinbao Gu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
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Yang X, Chen K, Wang Y, Yang D, Huang Y. The Sex Determination Cascade in the Silkworm. Genes (Basel) 2021; 12:genes12020315. [PMID: 33672402 PMCID: PMC7926724 DOI: 10.3390/genes12020315] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 12/22/2022] Open
Abstract
In insects, sex determination pathways involve three levels of master regulators: primary signals, which determine the sex; executors, which control sex-specific differentiation of tissues and organs; and transducers, which link the primary signals to the executors. The primary signals differ widely among insect species. In Diptera alone, several unrelated primary sex determiners have been identified. However, the doublesex (dsx) gene is highly conserved as the executor component across multiple insect orders. The transducer level shows an intermediate level of conservation. In many, but not all examined insects, a key transducer role is performed by transformer (tra), which controls sex-specific splicing of dsx. In Lepidoptera, studies of sex determination have focused on the lepidopteran model species Bombyx mori (the silkworm). In B. mori, the primary signal of sex determination cascade starts from Fem, a female-specific PIWI-interacting RNA, and its targeting gene Masc, which is apparently specific to and conserved among Lepidoptera. Tra has not been found in Lepidoptera. Instead, the B. mori PSI protein binds directly to dsx pre-mRNA and regulates its alternative splicing to produce male- and female-specific transcripts. Despite this basic understanding of the molecular mechanisms underlying sex determination, the links among the primary signals, transducers and executors remain largely unknown in Lepidoptera. In this review, we focus on the latest findings regarding the functions and working mechanisms of genes involved in feminization and masculinization in Lepidoptera and discuss directions for future research of sex determination in the silkworm.
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Affiliation(s)
- Xu Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kai Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaohui Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
| | - Dehong Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- Correspondence:
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Nakata M, Kikuchi Y, Iwami M, Takayanagi-Kiya S, Kiya T. Identification and characterization of sexually dimorphic neurons that express the sex-determining gene doublesex in the brain of silkmoth Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 129:103518. [PMID: 33421546 DOI: 10.1016/j.ibmb.2021.103518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/21/2020] [Accepted: 01/01/2021] [Indexed: 06/12/2023]
Abstract
Sexual differences in behavior are generated by sexually dimorphic neural circuits in animals. In insects, a highly conserved sex-determining gene doublesex (dsx) plays essential roles in the development of sexual dimorphisms. In the present study, to elucidate the neural basis of sexual differences in behaviors of silkmoth Bombyx mori, we investigated Bombyx mori dsx (Bmdsx) expression in the brains through development. In the brain, Bmdsx was differentially expressed in sex- and developmental stage-dependent manners. BmDSX protein-expressing cells were located in the dorsomedial region of the pupal and adult brains, and constituted two and one neural clusters in males and females, respectively. The number of BmDSX-positive cells was developmentally regulated and peaked at the early to middle pupal stages, suggesting that the sexually dimorphic neural circuits are established during this period. The detection of a neural activity marker protein BmHR38 suggested that the BmDSX-positive cells are not active during sexual behavior in both male and female moths, even though the cells in the vicinity of the BmDSX-positive cell clusters are active. These results imply that Bmdsx plays roles in the development of sexually dimorphic neural circuits, but the neural circuits are not related to sexual behavior in silkmoths.
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Affiliation(s)
- Masami Nakata
- Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Japan
| | - Yusuke Kikuchi
- Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Japan
| | - Masafumi Iwami
- Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Japan
| | - Seika Takayanagi-Kiya
- Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Japan
| | - Taketoshi Kiya
- Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Japan.
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11
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Yuzawa T, Matsuoka M, Sumitani M, Aoki F, Sezutsu H, Suzuki MG. Transgenic and knockout analyses of Masculinizer and doublesex illuminated the unique functions of doublesex in germ cell sexual development of the silkworm, Bombyx mori. BMC DEVELOPMENTAL BIOLOGY 2020; 20:19. [PMID: 32957956 PMCID: PMC7504827 DOI: 10.1186/s12861-020-00224-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/10/2020] [Indexed: 01/24/2023]
Abstract
Background Masculinizer (Masc) plays a pivotal role in male sex determination in the silkworm, Bombyx mori. Masc is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. The male isoform of Bmdsx (BmdsxM) induces male differentiation in somatic cells, while females express the female isoform of Bmdsx (BmdsxF), which promotes female differentiation in somatic cells. Our previous findings suggest that Masc could direct the differentiation of genetically female (ZW) germ cells into sperms. However, it remains unclear whether Masc directly induces spermatogenesis or if it promotes male differentiation in germ cells indirectly by inducing the expression of BmdsxM. Results In this study, we performed genetic analyses using the transgenic line that expressed Masc, as well as various Bmdsx knockout lines. We found that Masc-expressing females with a homozygous mutation in BmdsxM showed normal development in ovaries. The formation of testis-like tissues was abolished in these females. On the other hand, Masc-expressing females carrying a homozygous mutation in BmdsxF exhibited almost complete male-specific development in gonads and germ cells. These results suggest that BmdsxM has an ability to induce male development in germ cells as well as internal genital organs, while BmdsxF inhibits BmdsxM activity and represses male differentiation. To investigate whether MASC directly controls male-specific splicing of Bmdsx and identify RNAs that form complexes with MASC in testes, we performed RNA immunoprecipitation (RIP) using an anti-MASC antibody. We found that MASC formed a complex with AS1 lncRNA, which is a testis-specific factor involved in the male-specific splicing of Bmdsx pre-mRNA. Conclusions Taken together, our findings suggest that Masc induces male differentiation in germ cells by enhancing the production of BmdsxM. Physical interaction between MASC and AS1 lncRNA may be important for the BmdsxM expression in the testis. Unlike in the Drosophila dsx, BmdsxM was able to induce spermatogenesis in genetically female (ZW) germ cells. To the best of our knowledge, this is the first report that the role of dsx in germ cell sexual development is different between insect species.
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Affiliation(s)
- Tomohisa Yuzawa
- AIR WATER INC, 4-9-4 Hatchobori, Chuo-ku, Tokyo, 104-0032, Japan.,Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8562, Japan
| | - Misato Matsuoka
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8562, Japan.,SHINYUSHA, 1-12 Kanda Jimbocho, Chiyoda-ku, Tokyo, 101-0051, Japan
| | - Megumi Sumitani
- Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences, Owashi, Tsukuba, 305-8634, Japan
| | - Fugaku Aoki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8562, Japan
| | - Hideki Sezutsu
- Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences, Owashi, Tsukuba, 305-8634, Japan
| | - Masataka G Suzuki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8562, Japan.
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Deshmukh R, Lakhe D, Kunte K. Tissue-specific developmental regulation and isoform usage underlie the role of doublesex in sex differentiation and mimicry in Papilio swallowtails. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200792. [PMID: 33047041 PMCID: PMC7540742 DOI: 10.1098/rsos.200792] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 09/08/2020] [Indexed: 06/11/2023]
Abstract
Adaptive phenotypes often arise by rewiring existing developmental networks. Co-option of transcription factors in novel contexts has facilitated the evolution of ecologically important adaptations. doublesex (dsx) governs fundamental sex differentiation during embryonic stages and has been co-opted to regulate diverse secondary sexual dimorphisms during pupal development of holometabolous insects. In Papilio polytes, dsx regulates female-limited mimetic polymorphism, resulting in mimetic and non-mimetic forms. To understand how a critical gene such as dsx regulates novel wing patterns while maintaining its basic function in sex differentiation, we traced its expression through metamorphosis in P. polytes using developmental transcriptome data. We found three key dsx expression peaks: (i) eggs in pre- and post-ovisposition stages; (ii) developing wing discs and body in final larval instar; and (iii) 3-day pupae. We identified potential dsx targets using co-expression and differential expression analysis, and found distinct, non-overlapping sets of genes-containing putative dsx-binding sites-in developing wings versus abdominal tissue and in mimetic versus non-mimetic individuals. This suggests that dsx regulates distinct downstream targets in different tissues and wing colour morphs and has perhaps acquired new, previously unknown targets, for regulating mimetic polymorphism. Additionally, we observed that the three female isoforms of dsx were differentially expressed across stages (from eggs to adults) and tissues and differed in their protein structure. This may promote differential protein-protein interactions for each isoform and facilitate sub-functionalization of dsx activity across its isoforms. Our findings suggest that dsx employs tissue-specific downstream effectors and partitions its functions across multiple isoforms to regulate primary and secondary sexual dimorphism through insect development.
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Liu ZL, Xu J, Ling L, Yang DH, Chen SQ, Huang YP. MicroRNA-2738 regulates gene expression in the sex determination pathway in Bombyx mori. INSECT SCIENCE 2020; 27:646-654. [PMID: 31131541 DOI: 10.1111/1744-7917.12694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/28/2019] [Accepted: 05/04/2019] [Indexed: 06/09/2023]
Abstract
MicroRNAs (miRNAs) are a class of short, non-coding transcripts that bind to 3'-untranslated regions to trigger messenger RNA degradation or translational inhibition. Here we explored how miRNAs regulate sex determination in Bombyx mori, a lepidopteran model insect. Genes known to be involved in sex determination, BmPSI, Bmdsx, and BmMasc, are predicted targets of the species-specific miR-2738. Using a dual luciferase reporter assay in HEK293T cells, we confirmed that miR-2738 suppressed transcription of BmPSI, Bmdsx, and BmMasc. The levels of BmPSI and BmMasc were significantly down-regulated in B. mori miR-2738 overexpression. In contrast, the genetic disruption of miR-2738 using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 transgenic system increased the levels of BmPSI and BmMasc transcripts, whereas splicing of Bmdsx was unaltered by miR-2738 depletion or overexpression. Taken together, this study implicates miR-2738 as a minor regulator of sex determination genes in the silkworm.
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Affiliation(s)
- Zu-Lian Liu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, CAS, Shanghai, China
| | - Jun Xu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, CAS, Shanghai, China
| | - Lin Ling
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, CAS, Shanghai, China
| | - De-Hong Yang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, CAS, Shanghai, China
| | - Shu-Qing Chen
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, CAS, Shanghai, China
| | - Yong-Ping Huang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, CAS, Shanghai, China
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Xu J, Liu W, Yang D, Chen S, Chen K, Liu Z, Yang X, Meng J, Zhu G, Dong S, Zhang Y, Zhan S, Wang G, Huang Y. Regulation of olfactory-based sex behaviors in the silkworm by genes in the sex-determination cascade. PLoS Genet 2020; 16:e1008622. [PMID: 32520935 PMCID: PMC7307793 DOI: 10.1371/journal.pgen.1008622] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/22/2020] [Accepted: 05/04/2020] [Indexed: 11/28/2022] Open
Abstract
Insect courtship and mating depend on integration of olfactory, visual, and tactile cues. Compared to other insects, Bombyx mori, the domesticated silkworm, has relatively simple sexual behaviors as it cannot fly. Here by using CRISPR/Cas9 and electrophysiological techniques we found that courtship and mating behaviors are regulated in male silk moths by mutating genes in the sex determination cascade belonging to two conserved pathways. Loss of Bmdsx gene expression significantly reduced the peripheral perception of the major pheromone component bombykol by reducing expression of the product of the BmOR1 gene which completely blocked courtship in adult males. Interestingly, we found that mating behavior was regulated independently by another sexual differentiation gene, Bmfru. Loss of Bmfru completely blocked mating, but males displayed normal courtship behavior. Lack of Bmfru expression significantly reduced the perception of the minor pheromone component bombykal due to the down regulation of BmOR3 expression; further, functional analysis revealed that loss of the product of BmOR3 played a key role in terminating male mating behavior. Our results suggest that Bmdsx and Bmfru are at the base of the two primary pathways that regulate olfactory-based sexual behavior. The fundamental insect sexual behaviors, courtship and mating, result from successful integration of olfactory, vision, tactile and other complex innate behaviors. In the widely used insect model, Drosophila melanogaster, the sex determination cascade genes fruitless and doublesex are involved in the regulation of courtship and mating behaviors; however, little is known about the function of these sexual differentiation genes in regulating sex behaviors of Lepidoptera. Here we combine genetics and electrophysiology to investigate regulation pathway of sexual behaviors in the model lepidopteran insect, the domesticated silk moth, Bombyx mori. Our results support the presence of two genetic pathways in B. mori, named Bmdsx-BmOR1-bombykol and Bmfru-BmOR3-bombykal, which control distinct aspects of male sexual behavior that are modulated by olfaction. This is the first comprehensive report about the role of sex differentiation genes in the male sexual behavior in the silk moth.
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Affiliation(s)
- Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Wei Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dehong Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Shuqing Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Kai Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Zulian Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xu Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jing Meng
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Guanheng Zhu
- Education Ministry Key Laboratory of Integrated Management of Crop Disease and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Shuanglin Dong
- Education Ministry Key Laboratory of Integrated Management of Crop Disease and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yong Zhang
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
| | - Shuai Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail: (GW); (YH)
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (GW); (YH)
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15
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Li X, Liu Q, Liu H, Bi H, Wang Y, Chen X, Wu N, Xu J, Zhang Z, Huang Y, Chen H. Mutation of doublesex in Hyphantria cunea results in sex-specific sterility. PEST MANAGEMENT SCIENCE 2020; 76:1673-1682. [PMID: 31749278 DOI: 10.1002/ps.5687] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 10/22/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND The gene doublesex (dsx) plays pivotal roles in sex determination and controls sexually dimorphic development in certain insects. Importantly, it also displays a potential candidate target for pest management due to its sex-specific splicing. Therefore, we used CRISPR/Cas9-mediated gene disruption to investigate the function of dsx in Hyphantria cunea, an invasive forest pest. RESULT In the present study, we identified the dsx gene from H. cunea which showed a sex-biased expression pattern that was different from other lepidopteran insects. Referring to sex-specific functional analyses in Bombyx mori, we performed a site-specific knockout of the Hcdsx gene by using a CRISPR/Cas9 system, which induced severe abnormalities in external genitalia and some incomplete sex reversal phenotypes, which in turn led to reduced sex-specific fecundity. An alternative splicing pattern of Hcdsx was altered by CRISPR/Cas9-induced mutation, and alterations in splicing affected expression of downstream genes encoding pheromone binding protein 1, vg1 and vg2 (encoding vitellogenin), which contributed to the sex-specific sterility phenotypes in the Hcdsx mutants. CONCLUSION The Hcdsx gene plays important roles in sexual differentiation in H. cunea. Disruption of Hcdsx induced sex-specific sterility, demonstrating a potential application in control of this pest. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Xiaowei Li
- College of Forestry, Northwest A&F University, Yangling, China
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Qun Liu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Huihui Liu
- Key Laboratory of Forest Protection, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, State Forestry Administration, Beijing, China
| | - Honglun Bi
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Yaohui Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Xien Chen
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Ningning Wu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Jun Xu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Zhen Zhang
- Key Laboratory of Forest Protection, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, State Forestry Administration, Beijing, China
| | - Yongping Huang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China
| | - Hui Chen
- College of Forestry, Northwest A&F University, Yangling, China
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16
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Du Q, Wen L, Zheng SC, Bi HL, Huang YP, Feng QL, Liu L. Identification and functional characterization of doublesex gene in the testis of Spodoptera litura. INSECT SCIENCE 2019; 26:1000-1010. [PMID: 29808584 DOI: 10.1111/1744-7917.12608] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/22/2018] [Accepted: 05/10/2018] [Indexed: 06/08/2023]
Abstract
Fusion of the testis occurs in most Lepidoptera insects, including Spodoptera litura, an important polyphagous pest. Testicular fusion in S. litura is advantageous for male reproduction, and the molecular mechanism of fusion remains unknown. Doublesex influences the formation of genitalia, the behavior of courtship, and sexually dimorphic traits in fruit-fly and silkworm, and is essential for sexual differentiation. However, its purpose in the testis of S. litura remains unknown. The doublesex gene of S. litura (Sldsx) has male-specific SldsxM and female-specific SldsxF isoforms, and exhibits a higher expression level in the male testis. At the testicular fusion stage (L6D6), Sldsx attained the highest expression compared to the pre-fusion and post-fusion periods. Moreover, Sldsx had a higher expression in the peritoneal sheaths of testis than that of germ cells in the follicle. CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/Cas9) was applied to S. litura to determine the role of Sldsx. A mixture of single guide RNA messenger RNA and Cas9 protein (300 ng/μL each) was injected into eggs within 2 h following oviposition. CRISPR/Cas9 successfully induced genomic mutagenesis of Sldsx at G0 generation. The mutant males had smaller testis surrounded by less tracheae. Moreover, the mutant males had abnormal external genitalia and could not finish mating with wild-type females. Additionally, testes were fused for almost all mutant males. The results showed that Sldsx was not related to testicular fusion, and is required for both testis development and the formation and function of external genitalia in S. litura. The main roles of doublesex on the male are similar to other insects.
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Affiliation(s)
- Qian Du
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Liang Wen
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Si-Chun Zheng
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Hong-Lun Bi
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai, China
| | - Yong-Ping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai, China
| | - Qi-Li Feng
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Lin Liu
- Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
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Matsushima D, Kasahara R, Matsuno K, Aoki F, Suzuki MG. Involvement of Ecdysone Signaling in the Expression of the doublesex Gene during Embryonic Development in the Silkworm, Bombyx mori. Sex Dev 2019; 13:151-163. [PMID: 31487710 DOI: 10.1159/000502361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2019] [Indexed: 01/09/2023] Open
Abstract
Steroid hormones, represented by estrogen and testosterone, act as sex hormones that play an essential role in the sexual differentiation of vertebrates. However, it remains unclear whether ecdysteroids, typical steroid hormones in insects, function as sex hormones. In this study, we investigated whether ecdysteroids or ecdysone signals are involved in the sexual differentiation of the silkworm (Bombyx mori) embryo. Quantitative analysis using LC-MS/MS demonstrated that there was no significant difference in the 20-hydroxyecdysone (20E) titer between sexes during embryonic development. Consistent with this result, expression levels of 2 genes encoding ecdysteroid-phosphate phosphatase (EPPase) and ecdysone 20-hydroxylase (E20OHase), which are essential for the biosynthesis of ecdysone and 20E in eggs, did not show a significant difference between male and female embryos. Expression levels of ecdysone receptor (EcR) and E75, which is one of a small set of genes induced directly by 20E, were also similar between the 2 sexes. However, knockdown of EPPase and one isoform of EcR (EcR-A) resulted in decreased expression of Bombyx doublesex (Bmdsx), a master regulatory gene for sexual differentiation of the silkworm in both male and female embryos. In vitro analysis with cultured testes revealed that expression levels of Bmdsx were increased in a dose-dependent manner of the ecdysone analog, ponasterone A. These results suggest that ecdysone signaling may play a role in indirectly regulating the expression of some genes involved in sexual differentiation through inducing expression of Bmdsx in the silkworm.
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Wang Y, Chen X, Liu Z, Xu J, Li X, Bi H, Andongma AA, Niu C, Huang Y. Mutation of doublesex induces sex-specific sterility of the diamondback moth Plutella xylostella. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 112:103180. [PMID: 31278987 DOI: 10.1016/j.ibmb.2019.103180] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/28/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
DOUBLESEX (DSX): the downstream gene in the insect sex determination pathway, plays a critical role in sexual differentiation and development. The functions of dsx have been characterized in several model insect species. However, the molecular mechanism and functions of sex determination of dsx in Plutella xylostella, an agricultural pest, are still unknown. In present study, we identified a male-specific and three female-specific Pxdsx transcripts in P. xylostella. Phylogenetic analyses and multiple sequence alignment revealed that Pxdsx is highly conserved in lepidopterans. The CRISPR/Cas9 technology was used to induce mutations in the male-specific isoform, the female-specific isoform, and common regions of Pxdsx. Disruptions of Pxdsx sex-specific isoforms caused sex-specific defects in external genitals and partial sexual reversal. In addition, we found that female specific transcripts were detected in PxdsxM male mutants and male-specific transcripts were detected in PxdsxF female mutants. Mutations also caused changes in expression of several sex-biased genes and induced sex-specific sterility. This study demonstrates that Pxdsx plays a key role in sex determination of P. xylostella and suggests novel genetic control approaches for the management of P. xylostella.
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Affiliation(s)
- Yaohui Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China; Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xi'en Chen
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China
| | - Zulian Liu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China
| | - Jun Xu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China
| | - Xiaowei Li
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China
| | - Honglun Bi
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China
| | - Awawing A Andongma
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Changying Niu
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yongping Huang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, 200032, China.
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Chen X, Cao Y, Zhan S, Tan A, Palli SR, Huang Y. Disruption of sex-specific doublesex exons results in male- and female-specific defects in the black cutworm, Agrotis ipsilon. PEST MANAGEMENT SCIENCE 2019; 75:1697-1706. [PMID: 30520231 DOI: 10.1002/ps.5290] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/22/2018] [Accepted: 12/01/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Doublesex (dsx), the downstream gene in the insect sex-determination pathway, is a key regulator of sexually dimorphic development and behavior across a variety of insects. Manipulating expression of dsx could be useful in the genetic control of insects. However, information on the sex-specific function of dsx in non-model insects is lacking. RESULTS In this work, we isolated a dsx homolog, which is alternatively spliced into six female-specific and one male-specific isoforms, from an important agricultural pest, the black cutworm, Agrotis ipsilon. Studies on the expression of sex-specific Aidsx mRNA during embryonic development showed that the sixth hour post oviposition is the key stage for sex determination in A. ipsilon. Functional analysis of Aidsx was conducted using a CRISPR/Cas9 system targeting female- and male-specific Aidsx exons. Disruptions of sex-specific Aidsx exons resulted in sex-specific, sexually dimorphic defects in external genitals, gonads and antennae, and expression of sex-specific genes as well as production of offspring in both sexes. CONCLUSION Our results not only demonstrate that dsx is a key player determining A. ipsilon sexually dimorphic traits, but also provide a potential method for the genetic control of this pest. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Xien Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA
| | - Yanghui Cao
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Shuai Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Anjiang Tan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Wang Y, Zhao Q, Wan QX, Wang KX, Zha XF. P-element Somatic Inhibitor Protein Binding a Target Sequence in dsx Pre-mRNA Conserved in Bombyx mori and Spodoptera litura. Int J Mol Sci 2019; 20:ijms20092361. [PMID: 31086020 PMCID: PMC6539025 DOI: 10.3390/ijms20092361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/10/2019] [Accepted: 05/10/2019] [Indexed: 02/06/2023] Open
Abstract
Bombyx mori doublesex (Bmdsx) functions as a double-switch gene in the final step of the sex-determination cascade in the silkworm Bombyx mori. The P-element somatic inhibitor (PSI) protein in B. mori interacts with Bmdsx pre-mRNA in CE1 as an exonic splicing silencer to promote male-specific splicing of Bmdsx. However, the character of the interaction between BmPSI and Bmdsx pre-mRNA remains unclear. Electrophoretic mobility shift assay (EMSA) results showed that the four KH_1 motifs in BmPSI are all essential for the binding, especially the former two KH_1 motifs. Three active sites (I116, L127, and IGGI) in the KH_1 motif were found to be necessary for the binding through EMSA, circular dichroism (CD) spectroscopy, and isothermal titration calorimetry (ITC). The PSI homologous protein in S. litura (SlPSI) was purified and the binding of SlPSI and CE1 was verified. Compared with BmPSI, the mutant SlPSI proteins of I116 and IGGI lost their ability to bind to CE1. In conclusion, the binding of PSI and dsx pre-mRNA are generally conserved in both B. mori and S. litura. These findings provide clues for sex determination in Lepidoptera.
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Affiliation(s)
- Yao Wang
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Beibei, Chongqing 400715, China.
| | - Qin Zhao
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Beibei, Chongqing 400715, China.
| | - Qiu-Xing Wan
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Beibei, Chongqing 400715, China.
| | - Kai-Xuan Wang
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Beibei, Chongqing 400715, China.
| | - Xing-Fu Zha
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Beibei, Chongqing 400715, China.
- Chongqing Key Laboratory of Sericultural Science, Southwest University, Chongqing 400715, China.
- Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing 400715, China.
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Morita S, Ando T, Maeno A, Mizutani T, Mase M, Shigenobu S, Niimi T. Precise staging of beetle horn formation in Trypoxylus dichotomus reveals the pleiotropic roles of doublesex depending on the spatiotemporal developmental contexts. PLoS Genet 2019; 15:e1008063. [PMID: 30969957 PMCID: PMC6457530 DOI: 10.1371/journal.pgen.1008063] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 03/03/2019] [Indexed: 11/19/2022] Open
Abstract
Many scarab beetles have sexually dimorphic exaggerated horns that are an evolutionary novelty. Since the shape, number, size, and location of horns are highly diverged within Scarabaeidae, beetle horns are an attractive model for studying the evolution of sexually dimorphic and novel traits. In beetles including the Japanese rhinoceros beetle Trypoxylus dichotomus, the sex differentiation gene doublesex (dsx) plays a crucial role in sexually dimorphic horn formation during larval-pupal development. However, knowledge of when and how dsx drives the gene regulatory network (GRN) for horn formation to form sexually dimorphic horns during development remains elusive. To address this issue, we identified a Trypoxylus-ortholog of the sex determination gene, transformer (tra), that regulates sex-specific splicing of the dsx pre-mRNA, and whose loss of function results in sex transformation. By knocking down tra function at multiple developmental timepoints during larval-pupal development, we estimated the onset when the sex-specific GRN for horn formation is driven. In addition, we also revealed that dsx regulates different aspects of morphogenetic activities during the prepupal and pupal developmental stages to form appropriate morphologies of pupal head and thoracic horn primordia as well as those of adult horns. Based on these findings, we discuss the evolutionary developmental background of sexually dimorphic trait growth in horned beetles. Beetles in the family Scarabaeidae have various types of horns on their heads and thoraces, and the shape, size, number, and location of these horns are highly diversified within the group. In addition, many scarab beetle horns are sexually dimorphic. The acquisition of these evolutionarily novel horns, and the mechanisms for the diversification of these structures is an interesting question. To address this question, we focused on the rhinoceros beetle Tripoxylus dichotomus. Here we identified the exact developmental timepoints during which the morphological sexual dimorphism of horn primordia appears, estimated the onset of the developmental program for sexually dimorphic horn formation driven by doublesex, and revealed that doublesex regulates different aspects of cell activities during horn formation depending on particular spatiotemporal developmental contexts. Our study provides insights into regulatory shifts in these mechanisms during the evolution of sexually dimorphic traits in horned beetles.
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Affiliation(s)
- Shinichi Morita
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
| | - Toshiya Ando
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 38 Nishigonaka, Myodaiji, Okazaki, Japan
| | - Akiteru Maeno
- Mammalian Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Takeshi Mizutani
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
| | - Mutsuki Mase
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
| | - Shuji Shigenobu
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 38 Nishigonaka, Myodaiji, Okazaki, Japan
- NIBB Core Research Facilities, National Institute for Basic Biology, 38 Nishigonaka Myodaiji, Okazaki, Japan
| | - Teruyuki Niimi
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 38 Nishigonaka, Myodaiji, Okazaki, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
- * E-mail:
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22
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Roth A, Vleurinck C, Netschitailo O, Bauer V, Otte M, Kaftanoglu O, Page RE, Beye M. A genetic switch for worker nutrition-mediated traits in honeybees. PLoS Biol 2019; 17:e3000171. [PMID: 30897091 PMCID: PMC6428258 DOI: 10.1371/journal.pbio.3000171] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 02/13/2019] [Indexed: 12/14/2022] Open
Abstract
Highly social insects are characterized by caste dimorphism, with distinct size differences of reproductive organs between fertile queens and the more or less sterile workers. An abundance of nutrition or instruction via diet-specific compounds has been proposed as explanations for the nutrition-driven queen and worker polyphenism. Here, we further explored these models in the honeybee (Apis mellifera) using worker nutrition rearing and a novel mutational screening approach using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) method. The worker nutrition-driven size reduction of reproductive organs was restricted to the female sex, suggesting input from the sex determination pathway. Genetic screens on the sex determination genes in genetic females for size polyphenism revealed that doublesex (dsx) mutants display size-reduced reproductive organs irrespective of the sexual morphology of the organ tissue. In contrast, feminizer (fem) mutants lost the response to worker nutrition-driven size control. The first morphological worker mutants in honeybees demonstrate that the response to nutrition relies on a genetic program that is switched “ON” by the fem gene. Thus, the genetic instruction provided by the fem gene provides an entry point to genetically dissect the underlying processes that implement the size polyphenism. In honeybees, nutrition drives dimorphic size development of reproductive organs in fertile queens and sterile workers. A study using the first induced morphological mutants in honeybees demonstrates that this developmental plasticity requires a genetic program that is switched on by the “feminizer” gene. In honeybees, nutrition drives dimorphic size development of reproductive organs in fertile queens and sterile workers. The first induced morphological mutants in honeybees demonstrate that this developmental plasticity requires a genetic program that is switched “ON” by the feminizer (fem) gene.
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Affiliation(s)
- Annika Roth
- Institute of Evolutionary Genetics, Heinrich-Heine University Dusseldorf, Düsseldorf, Germany
| | - Christina Vleurinck
- Institute of Evolutionary Genetics, Heinrich-Heine University Dusseldorf, Düsseldorf, Germany
| | - Oksana Netschitailo
- Institute of Evolutionary Genetics, Heinrich-Heine University Dusseldorf, Düsseldorf, Germany
| | - Vivien Bauer
- Institute of Evolutionary Genetics, Heinrich-Heine University Dusseldorf, Düsseldorf, Germany
| | - Marianne Otte
- Institute of Evolutionary Genetics, Heinrich-Heine University Dusseldorf, Düsseldorf, Germany
| | - Osman Kaftanoglu
- School of Life Sciences, Arizona State University, Phoenix, Arizona, United States of America
| | - Robert E. Page
- School of Life Sciences, Arizona State University, Phoenix, Arizona, United States of America
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Martin Beye
- Institute of Evolutionary Genetics, Heinrich-Heine University Dusseldorf, Düsseldorf, Germany
- * E-mail:
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Kiuchi T, Sugano Y, Shimada T, Katsuma S. Two CCCH-type zinc finger domains in the Masc protein are dispensable for masculinization and dosage compensation in Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 104:30-38. [PMID: 30529581 DOI: 10.1016/j.ibmb.2018.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 12/04/2018] [Accepted: 12/06/2018] [Indexed: 06/09/2023]
Abstract
The Masculinizer (Masc) gene encodes a novel lepidopteran-specific protein that controls both masculinization and dosage compensation in the silkworm Bombyx mori. The Masc protein possesses two CCCH-type zinc finger domains (ZFs), a nuclear localization signal, and an 11-amino-acid region that is highly conserved among lepidopteran insects. Using a cell-based assay system, we revealed that two cysteine residues localized in the conserved region, but not ZFs, are required for masculinization. In addition, nuclear localization of the Masc protein is not associated with masculinizing activity. Because dosage compensation is considered to occur in the nucleus, we inferred that the two ZFs play a role in the establishment of dosage compensation. To investigate this hypothesis at the organism level, we utilized the CRISPR/Cas9 system and established three B. mori strains whose Masc is partially deleted at different regions. The strain lacking the 210 C-terminal amino acids of the Masc protein showed male-specific embryonic lethality due to its low abundance and/or instability. The male embryos of this strain expressed the female-type splice variants of B. mori doublesex and did not express the male-type mRNA of B. mori IGF-II mRNA-binding protein. Furthermore, mRNA levels of Z-linked genes were abnormally enhanced only in male embryos. In contrast, the strain lacking both ZFs grew normally and did not show any defective phenotypes including sexual differentiation and the expression of Z-linked genes, demonstrating that the two CCCH-type ZFs, which are conserved in lepidopteran Masc homologs, are dispensable for masculinization and dosage compensation.
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Affiliation(s)
- Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
| | - Yudai Sugano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Zhuo JC, Hu QL, Zhang HH, Zhang MQ, Jo SB, Zhang CX. Identification and functional analysis of the doublesex gene in the sexual development of a hemimetabolous insect, the brown planthopper. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 102:31-42. [PMID: 30237076 DOI: 10.1016/j.ibmb.2018.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/25/2018] [Accepted: 09/16/2018] [Indexed: 06/08/2023]
Abstract
In the sex determination cascade, the genes dsx (doublesex) in insects, mab-3 (male abnormal 3) in nematodes, and Dmrt1 (dsx/mab-3 related transcription factor-1) in vertebrates act as the base molecular switches and play important roles. Moreover, these genes share the same conserved feature domain-DNA-binding oligomerization domain (OD1), and female-specific dsx also has a conserved oligomerization domain 2 (OD2). Although sex determination and the functions of dsx in several holometabolous insects have been well documented, sex determination and the function of dsx in hemimetabolous insects remain a mystery. In this study, four dsx homologs were unexpectedly found in the Nilaparvata lugens (brown planthopper, BPH, order Hemiptera), which also showed a different evolutionary status. We found that only one of the four homologs, Nldsx, which has three alternative splicing variants (female-specific NldsxF, male-specific NldsxM, non-sex-specific NldsxC), was required in the sexual development of N. lugens. Compared with that of holometabolous species, the dsx of N. lugens contains a less conserved OD1, while the OD2 domain of BPH was not identifiable because the common region is poorly conserved, and the female-specific region is short. RNAi-mediated knockdown of Nldsx in female BPH resulted in a larger body size with a normal abdomen and reproductive system, while no changes in fertility were noted. However, adult males with RNA interference knockdown of NldsxM in nymphs became pseudofemales, were infertile, had abnormal copulatory organs, and had impassable deferent ducts with hyperplastic walls; additionally, the pseudofemales could not produce the normal courtship signals. Our results suggest that dsx plays a critical role in male BPH somatic development and mating behavior. This is the first study to show that dsx is essential for sexual development in a hemipteran species.
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Affiliation(s)
- Ji-Chong Zhuo
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China
| | - Qing-Ling Hu
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China
| | - Hou-Hong Zhang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China
| | - Meng-Qiu Zhang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China
| | - Song Bok Jo
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China; Kim Jong Suk University of Education, Democratic People's Republic of Korea
| | - Chuan-Xi Zhang
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China.
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25
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In vivo masculinizing function of the Ostrinia furnacalis Masculinizer gene. Biochem Biophys Res Commun 2018; 503:1768-1772. [DOI: 10.1016/j.bbrc.2018.07.111] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 07/22/2018] [Indexed: 11/22/2022]
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26
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Candidate genes associated with color morphs of female-limited polymorphisms of the damselfly Ischnura senegalensis. Heredity (Edinb) 2018; 122:81-92. [PMID: 29713090 DOI: 10.1038/s41437-018-0076-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 11/09/2022] Open
Abstract
Many Odonata species exhibit female-limited polymorphisms, where one morph is similar to the conspecific male in body color and other traits (andromorph), whereas one or more other morphs differ from the male (gynomorphs). Here we investigated the differentially expressed transcripts (DETs) among males and two female morph groups (gynomorphs and andromorphs) using RNA-seq to identify candidate transcripts encoding female-limited polymorphisms in the damselfly Ischnura senegalensis. Seven DETs that had significantly different expression levels between males and gynomorphs, but not between males and andromorphs, were identified. The expression levels of four of these candidate genes, doublesex (dsx), black, ebony, and chaoptin (chp), were selected for further analysis using qRT-PCR. Sequence analysis of the dsx amplicons revealed that this gene produced at least three transcripts. Two short transcripts were mainly expressed in males and andromorphs, whereas the long transcript was specifically expressed in both morph female groups; that is, the expression pattern of the dsx splice variants in andromorphs was an intermediate between that of males and gynomorphs. Because the dsx gene functions as a transcription factor that regulates the sex-specific expression of multiple genes, its splice variants in I. senegalensis may explain why the andromorph is female but exhibits some masculinized traits. Because we did not detect different coding sequences of the candidate genes among the different morphs, a diallelic genomic region controlling alternative splicing of dsx, thus determining female-limited polymorphism in I. senegalensis most likely lies in a non-coding region of the dsx gene or in a gene upstream of it.
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KATSUMA S, KIUCHI T, KAWAMOTO M, FUJIMOTO T, SAHARA K. Unique sex determination system in the silkworm, Bombyx mori: current status and beyond. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2018; 94:205-216. [PMID: 29760316 PMCID: PMC6021594 DOI: 10.2183/pjab.94.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/19/2018] [Indexed: 06/02/2023]
Abstract
The silkworm Bombyx mori has been used for silk production for over 5,000 years. In addition to its contribution to sericulture, B. mori has played an important role in the field of genetics. Classical genetic studies revealed that a gene(s) with a strong feminizing activity is located on the W chromosome, but this W-linked feminizing gene, called Feminizer (Fem), had not been cloned despite more than 80 years of study. In 2014, we discovered that Fem is a precursor of a single W chromosome-derived PIWI-interacting RNA (piRNA). Fem-derived piRNA binds to PIWI protein, and this complex then cleaves the mRNA of the Z-linked Masculinizer (Masc) gene, which encodes a protein required for both masculinization and dosage compensation. These findings showed that the piRNA-mediated interaction between the two sex chromosomes is the primary signal for the sex determination cascade in B. mori. In this review, we summarize the history, current status, and perspective of studies on sex determination and related topics in B. mori.
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Affiliation(s)
- Susumu KATSUMA
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takashi KIUCHI
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Munetaka KAWAMOTO
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Toshiaki FUJIMOTO
- Laboratory of Applied Entomology, Faculty of Agriculture, Iwate University, Iwate, Japan
| | - Ken SAHARA
- Laboratory of Applied Entomology, Faculty of Agriculture, Iwate University, Iwate, Japan
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Fujinaga D, Kohmura Y, Okamoto N, Kataoka H, Mizoguchi A. Insulin-like growth factor (IGF)-like peptide and 20-hydroxyecdysone regulate the growth and development of the male genital disk through different mechanisms in the silkmoth, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 87:35-44. [PMID: 28610907 DOI: 10.1016/j.ibmb.2017.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 06/07/2017] [Accepted: 06/08/2017] [Indexed: 06/07/2023]
Abstract
It is well established that ecdysteroids play pivotal roles in the regulation of insect molting and metamorphosis. However, the mechanisms by which ecdysteroids regulate the growth and development of adult organs after pupation are poorly understood. Recently, we have identified insulin-like growth factor (IGF)-like peptides (IGFLPs), which are secreted after pupation under the control of 20-hydroxyecdysone (20E). In the silkmoth, Bombyx mori, massive amounts of Bombyx-IGFLP (BIGFLP) are present in the hemolymph during pupal-adult development, suggesting its importance in the regulation of adult tissue growth. Thus, we hypothesized that the growth and development of adult tissues including imaginal disks are regulated by the combined effects of BIGFLP and 20E. In this study, we investigated the growth-promoting effects of BIGFLP and 20E using the male genital disks of B. mori cultured ex vivo, and further analyzed the cell signaling pathways mediating hormone actions. We demonstrate that 20E induces the elongation of genital disks, that both hormones stimulate protein synthesis in an additive manner, and that BIGFLP and 20E exert their effects through the insulin/IGF signaling pathway and mitogen-activated protein kinase pathway, respectively. These results show that the growth and development of the genital disk are coordinately regulated by both BIGFLP and 20E.
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Affiliation(s)
- Daiki Fujinaga
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Yusuke Kohmura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Naoki Okamoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hiroshi Kataoka
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan.
| | - Akira Mizoguchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
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29
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Xu J, Zhan S, Chen S, Zeng B, Li Z, James AA, Tan A, Huang Y. Sexually dimorphic traits in the silkworm, Bombyx mori, are regulated by doublesex. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 80:42-51. [PMID: 27867075 DOI: 10.1016/j.ibmb.2016.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/19/2016] [Accepted: 11/16/2016] [Indexed: 06/06/2023]
Abstract
The DM domain genes, doublesex (dsx) in insects, or their structural homologs, male abnormal 3 (mab-3) in nematodes and Dmrt1 (doublesex and mab-3-related transcription factor 1) in mammals, are downstream regulators of the sex determination pathway that control sexually dimorphic development. Despite the functional importance of dsx and its potential applications in sterile insect technologies (SITs), the mechanisms by which it controls sexually dimorphic traits and the subsequent developmental gene networks in insects are poorly understood. Phylogenetic analyses indicate that insect dsx genes have sex-specific alternative splicing isoforms, whereas other taxa do not. We exploited genome editing and transgenesis technologies to induce mutations in either the male-specific isoform (dsxM) or common region (dsxC) of dsx in the somatic tissues of the lepidopteran model insect Bombyx mori. Disruptions of gene function produced either male-specific sexually-dimorphic defects or intersexual phenotypes; these results differ from those observed in other insects, including Drosophila melanogaster. Our data provide insights into the divergence of the insect sex determination pathways related to the most conserved downstream component dsx.
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Affiliation(s)
- Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuai Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shuqing Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baosheng Zeng
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiqian Li
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Anthony A James
- Department of Microbiology & Molecular Genetics and Molecular Biology & Biochemistry, University of California, Irvine, CA 92697-3900, United States.
| | - Anjiang Tan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
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30
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Sakai H, Sumitani M, Chikami Y, Yahata K, Uchino K, Kiuchi T, Katsuma S, Aoki F, Sezutsu H, Suzuki MG. Transgenic Expression of the piRNA-Resistant Masculinizer Gene Induces Female-Specific Lethality and Partial Female-to-Male Sex Reversal in the Silkworm, Bombyx mori. PLoS Genet 2016; 12:e1006203. [PMID: 27579676 PMCID: PMC5007099 DOI: 10.1371/journal.pgen.1006203] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/28/2016] [Indexed: 12/12/2022] Open
Abstract
In Bombyx mori (B. mori), Fem piRNA originates from the W chromosome and is responsible for femaleness. The Fem piRNA-PIWI complex targets and cleaves mRNAs transcribed from the Masc gene. Masc encodes a novel CCCH type zinc-finger protein and is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. In the present study, several silkworm strains carrying a transgene, which encodes a Fem piRNA-resistant Masc mRNA (Masc-R), were generated. Forced expression of the Masc-R transgene caused female-specific lethality during the larval stages. One of the Masc-R strains weakly expressed Masc-R in various tissues. Females heterozygous for the transgene expressed male-specific isoform of the Bombyx homolog of insulin-like growth factor II mRNA-binding protein (ImpM) and Bmdsx. All examined females showed a lower inducibility of vitellogenin synthesis and exhibited abnormalities in the ovaries. Testis-like tissues were observed in abnormal ovaries and, notably, the tissues contained considerable numbers of sperm bundles. Homozygous expression of the transgene resulted in formation of the male-specific abdominal segment in adult females and caused partial male differentiation in female genitalia. These results strongly suggest that Masc is an important regulatory gene of maleness in B. mori.
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Affiliation(s)
- Hiroki Sakai
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Megumi Sumitani
- Transgenic Silkworm Research Unit, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Yasuhiko Chikami
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Kensuke Yahata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Keiro Uchino
- Transgenic Silkworm Research Unit, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Fugaku Aoki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Hideki Sezutsu
- Transgenic Silkworm Research Unit, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Masataka G. Suzuki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
- * E-mail:
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Guo J, Jiang F, Yi J, Liu X, Zhang G. Transcriptome characterization and gene expression analysis related to sexual dimorphism in the ghost moth, Thitarodes pui, a host of Ophiocordyceps sinensis. Gene 2016; 588:134-40. [PMID: 27182053 DOI: 10.1016/j.gene.2016.05.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 04/30/2016] [Accepted: 05/11/2016] [Indexed: 01/10/2023]
Abstract
Thitarodes pui is one of the host species of the Chinese caterpillar fungus Ophiocordyceps sinensis as a traditional Chinese medicine with economic and medical importance. The pupal and adult stages of T. pui are sexually dimorphic. In order to elucidate the molecular mechanisms involved in the sexually dimorphic development of T. pui, we compared the transcriptomes of female and male pupae and adults. We obtained 15,881,734, 16,962,086, 17,514,743, and 17,770,904 clean reads from female pupae, male pupae, female adults, and male adults, respectively. The reads obtained from the four samples were pooled and assembled into 65,165 unigenes, 23,597 of which were annotated. Candidate genes involved in sexual development were identified and analysed. Gene expression analysis revealed that 1406 genes were differentially expressed in male and female pupae, 448 of which were up-regulated in males and 958 were up-regulated in females. A total of 2025 genes were differentially expressed in male and females adults, 1304 of which were up-regulated in males and 721 were up-regulated in females. The functional enrichment of the differentially expressed genes indicated that reproduction and cuticle synthesis were regulated differently between the sexes. The transcriptome data obtained provide significant information regarding the genes involved in sexually dimorphic development, which will improve our understanding of the molecular mechanisms related to sexual dimorphism and helpful for the moth mass rearing which would provide enough host insects for the sustainable utilization of O. sinensis.
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Affiliation(s)
- Jixing Guo
- State Key Laboratory for Biocontrol, Sun Yat-sen University, Xingangxi Road 135, Guangzhou 510275, PR China
| | - Fengze Jiang
- State Key Laboratory for Biocontrol, Sun Yat-sen University, Xingangxi Road 135, Guangzhou 510275, PR China
| | - Jiequn Yi
- State Key Laboratory for Biocontrol, Sun Yat-sen University, Xingangxi Road 135, Guangzhou 510275, PR China
| | - Xin Liu
- State Key Laboratory for Biocontrol, Sun Yat-sen University, Xingangxi Road 135, Guangzhou 510275, PR China
| | - Guren Zhang
- State Key Laboratory for Biocontrol, Sun Yat-sen University, Xingangxi Road 135, Guangzhou 510275, PR China.
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Long D, Lu W, Hao Z, Xiang Z, Zhao A. Highly efficient and inducible DNA excision in transgenic silkworms using the FLP/FRT site-specific recombination system. Transgenic Res 2016; 25:795-811. [DOI: 10.1007/s11248-016-9970-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/16/2016] [Indexed: 12/11/2022]
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Sugano Y, Kokusho R, Ueda M, Fujimoto M, Tsutsumi N, Shimada T, Kiuchi T, Katsuma S. Identification of a bipartite nuclear localization signal in the silkworm Masc protein. FEBS Lett 2016; 590:2256-61. [DOI: 10.1002/1873-3468.12246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 05/30/2016] [Accepted: 05/30/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Yudai Sugano
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Ryuhei Kokusho
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Masamichi Ueda
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Masaru Fujimoto
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Nobuhiro Tsutsumi
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences; The University of Tokyo; Japan
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Tan D, Tong XL, Hu H, Wu SY, Li CL, Xiong G, Xiang ZH, Dai FY, Lu C. Morphological characterization and molecular mapping of an irradiation-induced Speckled mutant in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2016; 25:93-104. [PMID: 26661290 DOI: 10.1111/imb.12205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Speckled (Spc), an X-ray-induced lethal mutant of Bombyx mori, exhibits a mosaic dark-brown-spotted larval epidermis in both sexes and egg-laying problems only in females. Here, we report the morphological characterization and molecular mapping of the Spc mutant. Morphological investigations revealed that the epidermal ultrastructure of the small, dark-brown spots was more dense than that of the white regions in both Spc/+ mutants and wild type, and that the lethality of the Spc/Spc mutants occurred during early embryogenesis. Furthermore, the ovarioles and ovipositor were disconnected in approximately 85.5% of Spc/+ females, a further 2.5% had a connection between the ovarioles and ovipositor that was too narrow to lay eggs. The remaining females showed a normal connection similar to that of the wild type. We successfully narrowed down the location of the Spc mutation to a region on chromosome 4 that was ∼1041 kb long. Gene-prediction analysis identified 25 candidate genes in this region. Chromosome structure analysis indicated that a ∼305 kb deletion was included in the mapping region. Temporal and spatial reverse transcription PCR (RT-PCR) analysis showed that several genes in the mapped region are associated with the Spc mutant. Although the genes responsible for the Spc mutation were not definitively identified, our results further the current understanding of the complex mechanism underlying the multiple morphological defects in Spc mutants.
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Affiliation(s)
- D Tan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - X-L Tong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - H Hu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - S-Y Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - C-L Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - G Xiong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Z-H Xiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - F-Y Dai
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - C Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
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Duan J, Meng X, Ma S, Wang F, Guo H, Zhang L, Zhao P, Kan Y, Yao L, Xia Q. The C-terminus of DSX(F5) protein acts as a novel regulatory domain in Bombyx mori. Transgenic Res 2016; 25:491-7. [PMID: 26975733 DOI: 10.1007/s11248-016-9946-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/24/2016] [Indexed: 11/26/2022]
Abstract
The doublesex gene regulates the somatic sexual development of Bombyx mori by alternatively splicing into sex-specific splice forms. In our previous study, the splice form Bmdsx (F7) , which encodes the BmDSX(F5) protein, was found to be expressed in a female-specific manner and to contain a novel C-terminus. In this study, we aimed to investigate the role of this C-terminus. Two transgenic lines, L1 and L2, were constructed to ectopically express Bmdsx (F7) in males. Phenotype and W chromosome-specific polymerase chain reaction (PCR) analysis showed that developmental abnormalities and sex reversal did not occur. Moreover, the sex ratio was also normal. Quantitative PCR revealed that the expression levels of SP1 and Vg were upregulated in the fat body of transgenic males. Additionally, the expression level of PBP was downregulated in the antenna of transgenic males. The results suggested that the C-terminus of BmDSX(F5) functioned as a regulatory domain during regulation of downstream target gene expression and that BmDSX(F5) participated in the sexual development of somatic cells together with other DSX proteins in B. mori.
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Affiliation(s)
- Jianping Duan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China
- Henan Provincial Key Laboratory of Funiu Mountain Insect Biology and School of Education, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Xianxin Meng
- Henan Provincial Key Laboratory of Funiu Mountain Insect Biology and School of Education, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Sanyuan Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China
| | - Feng Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China
| | - Huozhen Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China
| | - Liying Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China
| | - Yunchao Kan
- Henan Provincial Key Laboratory of Funiu Mountain Insect Biology and School of Education, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Lunguang Yao
- Henan Provincial Key Laboratory of Funiu Mountain Insect Biology and School of Education, Nanyang Normal University, Nanyang, 473061, People's Republic of China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
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siRNA-Mediated Silencing of doublesex during Female Development of the Dengue Vector Mosquito Aedes aegypti. PLoS Negl Trop Dis 2015; 9:e0004213. [PMID: 26544686 PMCID: PMC4636264 DOI: 10.1371/journal.pntd.0004213] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/14/2015] [Indexed: 12/30/2022] Open
Abstract
The development of sex-specific traits, including the female-specific ability to bite humans and vector disease, is critical for vector mosquito reproduction and pathogen transmission. Doublesex (Dsx), a terminal transcription factor in the sex determination pathway, is known to regulate sex-specific gene expression during development of the dengue fever vector mosquito Aedes aegypti. Here, the effects of developmental siRNA-mediated dsx silencing were assessed in adult females. Targeting of dsx during A. aegypti development resulted in decreased female wing size, a correlate for body size, which is typically larger in females. siRNA-mediated targeting of dsx also resulted in decreased length of the adult female proboscis. Although dsx silencing did not impact female membrane blood feeding or mating behavior in the laboratory, decreased fecundity and fertility correlated with decreased ovary length, ovariole length, and ovariole number in dsx knockdown females. Dsx silencing also resulted in disruption of olfactory system development, as evidenced by reduced length of the female antenna and maxillary palp and the sensilla present on these structures, as well as disrupted odorant receptor expression. Female lifespan, a critical component of the ability of A. aegypti to transmit pathogens, was also significantly reduced in adult females following developmental targeting of dsx. The results of this investigation demonstrate that silencing of dsx during A. aegypti development disrupts multiple sex-specific morphological, physiological, and behavioral traits of adult females, a number of which are directly or indirectly linked to mosquito reproduction and pathogen transmission. Moreover, the olfactory phenotypes observed connect Dsx to development of the olfactory system, suggesting that A. aegypti will be an excellent system in which to further assess the developmental genetics of sex-specific chemosensation. Only adult female mosquitoes, which require blood meals for reproduction, bite humans and spread diseases. The genes that regulate development of sex-specific traits may therefore represent novel targets for mosquito control. Here, we examine the effects of silencing the sex-determination gene doublesex (dsx) during development of the human disease vector mosquito Aedes aegypti. Targeting of dsx resulted in decreased length of the female wing and proboscis, ovary and reproductive defects, and disruption of olfactory system development. Female lifespan, a critical aspect of mosquito pathogen transmission, was also significantly reduced in adult females following developmental targeting of dsx. The results of this investigation demonstrate that silencing of dsx during A. aegypti development disrupts multiple sex-specific morphological, physiological, and behavioral traits of adult females, a number of which are directly or indirectly linked to mosquito reproduction and pathogen transmission. The results obtained also connect Dsx to development of the mosquito olfactory system, suggesting that A. aegypti will be an excellent system in which to further assess the developmental genetics of sex-specific chemosensation.
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Lee J, Kiuchi T, Kawamoto M, Shimada T, Katsuma S. Identification and functional analysis of a Masculinizer orthologue in Trilocha varians (Lepidoptera: Bombycidae). INSECT MOLECULAR BIOLOGY 2015; 24:561-569. [PMID: 26154510 DOI: 10.1111/imb.12181] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We recently showed that the Masculinizer gene (Masc) plays a primary role in sex determination in the lepidopteran model insect Bombyx mori. However, it remains unknown whether this Masc protein-dependent sex determination system is conserved amongst lepidopteran insects or within the family Bombycidae. Here we cloned and characterized a Masc homologue (TvMasc) in Trilocha varians (Lepidoptera: Bombycidae), a species closely related to B. mori. To elucidate the role of TvMasc in the sex determination cascade of T. varians, TvMasc expression was knocked down in early embryos by the injection of small interfering RNAs (siRNAs) that targeted TvMasc mRNAs. Both female- and male-type splice variants of Tvdsx, a doublesex (dsx) homologue in T. varians were observed in control siRNA-injected embryos. By contrast, only female-type splice variants were observed in TvMasc siRNA-injected embryos. These results indicate that the TvMasc protein directly or indirectly regulates the splicing patterns of Tvdsx. Furthermore, we found that male-type splice variants of B. mori dsx (Bmdsx) were produced in TvMasc-overexpressing BmN4 cells. The mRNA level of B. mori Imp, a gene whose product induces male-specific Bmdsx splicing also increased. These results suggest that Masc genes play similar roles in the sex-determination cascade in Bombycidae.
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Affiliation(s)
- J Lee
- Department of Agricultural and Environmental Biology Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - T Kiuchi
- Department of Agricultural and Environmental Biology Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - M Kawamoto
- Department of Agricultural and Environmental Biology Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - T Shimada
- Department of Agricultural and Environmental Biology Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - S Katsuma
- Department of Agricultural and Environmental Biology Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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Abstract
The W chromosome of the silkworm Bombyx mori has been known to determine femaleness for more than 80 years. However, the feminizing gene has not been molecularly identified, because the B. mori W chromosome is almost fully occupied by a large number of transposable elements. The W chromosome-derived feminizing factor of B. mori was recently shown to be a female-specific PIWI-interacting RNA (piRNA). piRNAs are small RNAs that potentially repress invading “non-self” elements (e.g., transposons and virus-like elements) by associating with PIWI proteins. Our results revealed that female-specific piRNA precursors, which we named Fem, are transcribed from the sex-determining region of the W chromosome at the early embryonic stage and are processed into a single mature piRNA (Fem piRNA). Fem piRNA forms a complex with Siwi (silkworm Piwi), which cleaves a protein-coding mRNA transcribed from the Z chromosome. RNA interference of this Z-linked gene, which we named Masc, revealed that this gene encodes a protein required for masculinization and dosage compensation. Fem and Masc both participate in the ping-pong cycle of the piRNA amplification loop by associating with the 2 B. mori PIWI proteins Siwi and BmAgo3 (silkworm Ago3), respectively, indicating that the piRNA-mediated interaction between the 2 sex chromosomes is the primary signal for the B. mori sex determination cascade. Fem is a non-transposable repetitive sequence on the W chromosome, whereas Masc is a single-copy protein-coding gene. It is of great interest how the piRNA system recognizes “self ”Masc mRNA as “non-self” RNA.
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Affiliation(s)
- Susumu Katsuma
- a Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences ; The University of Tokyo ; Bunkyo-ku , Tokyo , Japan
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Katsuma S, Sugano Y, Kiuchi T, Shimada T. Two Conserved Cysteine Residues Are Required for the Masculinizing Activity of the Silkworm Masc Protein. J Biol Chem 2015; 290:26114-24. [PMID: 26342076 DOI: 10.1074/jbc.m115.685362] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Indexed: 11/06/2022] Open
Abstract
We have recently discovered that the Masculinizer (Masc) gene encodes a CCCH tandem zinc finger protein, which controls both masculinization and dosage compensation in the silkworm Bombyx mori. In this study, we attempted to identify functional regions or residues that are required for the masculinizing activity of the Masc protein. We constructed a series of plasmids that expressed the Masc derivatives and transfected them into a B. mori ovary-derived cell line, BmN-4. To assess the masculinizing activity of the Masc derivatives, we investigated the splicing patterns of B. mori doublesex (Bmdsx) and the expression levels of B. mori IGF-II mRNA-binding protein, a splicing regulator of Bmdsx, in Masc cDNA-transfected BmN-4 cells. We found that two zinc finger domains are not required for the masculinizing activity. We also identified that the C-terminal 288 amino acid residues are sufficient for the masculinizing activity of the Masc protein. Further detailed analyses revealed that two cysteine residues, Cys-301 and Cys-304, in the highly conserved region among lepidopteran Masc proteins are essential for the masculinizing activity in BmN-4 cells. Finally, we showed that Masc is a nuclear protein, but its nuclear localization is not tightly associated with the masculinizing activity.
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Affiliation(s)
- Susumu Katsuma
- From the Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yudai Sugano
- From the Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takashi Kiuchi
- From the Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Toru Shimada
- From the Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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Fukui T, Kawamoto M, Shoji K, Kiuchi T, Sugano S, Shimada T, Suzuki Y, Katsuma S. The Endosymbiotic Bacterium Wolbachia Selectively Kills Male Hosts by Targeting the Masculinizing Gene. PLoS Pathog 2015; 11:e1005048. [PMID: 26172536 PMCID: PMC4501725 DOI: 10.1371/journal.ppat.1005048] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 06/25/2015] [Indexed: 12/30/2022] Open
Abstract
Pathogens are known to manipulate the reproduction and development of their hosts for their own benefit. Wolbachia is an endosymbiotic bacterium that infects a wide range of insect species. Wolbachia is known as an example of a parasite that manipulates the sex of its host's progeny. Infection of Ostrinia moths by Wolbachia causes the production of all-female progeny, however, the mechanism of how Wolbachia accomplishes this male-specific killing is unknown. Here we show for the first time that Wolbachia targets the host masculinizing gene of Ostrinia to accomplish male-killing. We found that Wolbachia-infected O. furnacalis embryos do not express the male-specific splice variant of doublesex, a gene which acts at the downstream end of the sex differentiation cascade, throughout embryonic development. Transcriptome analysis revealed that Wolbachia infection markedly reduces the mRNA level of Masc, a gene that encodes a protein required for both masculinization and dosage compensation in the silkworm Bombyx mori. Detailed bioinformatic analysis also elucidated that dosage compensation of Z-linked genes fails in Wolbachia-infected O. furnacalis embryos, a phenomenon that is extremely similar to that observed in Masc mRNA-depleted male embryos of B. mori. Finally, injection of in vitro transcribed Masc cRNA into Wolbachia-infected embryos rescued male progeny. Our results show that Wolbachia-induced male-killing is caused by a failure of dosage compensation via repression of the host masculinizing gene. Our study also shows a novel strategy by which a pathogen hijacks the host sex determination cascade. Pathogens are known to manipulate the physiology, behavior, and reproduction of their hosts for their own benefit. The endosymbiotic bacterium Wolbachia is known to manipulate the sex of its host's progeny. Male-killing is one of the phenotypes that Wolbachia induces, but the mechanism of how Wolbachia induces sex-specific death is unknown. Here we found a marked down-regulation of Masc, a lepidopteran-specific zinc finger protein gene, in embryos that are produced by Wolbachia-infected Ostrinia moths. We also observed that dosage compensation fails in Wolbachia-infected Ostrinia embryos. The findings of this study and our previous study using a lepidopteran model insect Bombyx mori indicate that Wolbachia has evolved to hijack the Masc-dependent, lepidopteran insect-specific sex determination system by capturing an unknown factor during Wolbachia-host coevolution.
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Affiliation(s)
- Takahiro Fukui
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Munetaka Kawamoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Keisuke Shoji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Sumio Sugano
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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Fujii T, Abe H, Kawamoto M, Banno Y, Shimada T. Positional cloning of the sex-linked giant egg (Ge) locus in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2015; 24:213-221. [PMID: 25469867 DOI: 10.1111/imb.12150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The giant egg (Ge) locus is a Z-linked mutation that leads to the production of large eggs. Cytological observations suggest that an unusual translocation of a large fragment of the W chromosome bearing a putative egg size-determining gene, Esd, gave rise to giant egg mutants. However, there is currently no molecular evidence confirming either a W-Z translocation or the presence of Esd on the W chromosome. To elucidate the origin of giant egg mutants, we performed positional cloning. We observed that the Bombyx mori. orthologue of the human Phytanoyl-CoA dioxygenase domain containing 1 gene (PHYHD1) is disrupted in giant egg mutants. PHYHD1 is highly conserved in eukaryotes and is predicted to be a Fe(II) and 2-oxoglutarate-dependent oxygenase. Exon skipping in one of the two available Ge mutants is probably caused by the insertion of a non-long terminal repeat transposon into intron 4 in the vicinity of the 5' splice site. Segmental duplication in Ge(2) , an independent allele, was caused by unequal recombination between short interspersed elements inserted into introns 3 and 5. Our results indicate that (1) Bombyx PHYHD1 is responsible for the Ge mutants and that (2) the Ge locus is unrelated to the W-linked putative Esd. To our knowledge, this is the first report describing the phenotypic defects caused by mutations in PHYHD1 orthologues.
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Affiliation(s)
- T Fujii
- Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan; Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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Verhulst EC, van de Zande L. Double nexus--Doublesex is the connecting element in sex determination. Brief Funct Genomics 2015; 14:396-406. [PMID: 25797692 PMCID: PMC4652034 DOI: 10.1093/bfgp/elv005] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In recent years, our knowledge of the conserved master-switch gene doublesex (dsx) and its function in regulating the development of dimorphic traits in insects has deepened considerably. Here, a comprehensive overview is given on the properties of the male- and female-specific dsx transcripts yielding DSXF and DSXM proteins in Drosophila melanogaster, and the many downstream targets that they regulate. As insects have cell-autonomous sex determination, it was assumed that dsx would be expressed in every somatic cell, but recent research showed that dsx is expressed only when a cell is required to show its sexual identity through function or morphology. This spatiotemporal regulation of dsx expression has not only been established in D. melanogaster but in all insect species studied. Gradually, it has been appreciated that dsx could no longer be viewed as the master-switch gene orchestrating sexual development and behaviour in each cell, but instead should be viewed as the interpreter for the sexual identity of the cell, expressing this identity only on request, making dsx the central nexus of insect sex determination.
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Kawamoto M, Koga H, Kiuchi T, Shoji K, Sugano S, Shimada T, Suzuki Y, Katsuma S. Sexually biased transcripts at early embryonic stages of the silkworm depend on the sex chromosome constitution. Gene 2015; 560:50-6. [PMID: 25615878 DOI: 10.1016/j.gene.2015.01.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 12/18/2014] [Accepted: 01/20/2015] [Indexed: 11/24/2022]
Abstract
In the silkworm, Bombyx mori, females are heterogametic (WZ) whereas males have two Z chromosomes. Femaleness of B. mori is determined by the presence of the W chromosome, suggesting that there is a dominant feminizing gene on this chromosome. Recently, by transcriptome analysis of B. mori embryos, we discovered that a single W-chromosome-derived PIWI-interacting RNA (piRNA) is the long-sought primary determinant of femaleness in B. mori. However, sexual bias in the transcriptome of B. mori early embryos has not yet been well characterized. Using deep sequencing data from molecularly sexed RNA of B. mori embryos, we identified and characterized 157 transcripts that are statistically differentially expressed between male and female early embryos. Most of the female-biased transcripts were transposons or repeat sequences that are produced presumably from the W chromosome. Bioinformatic analysis revealed that these repetitive sequences are piRNA precursors. In contrast, male-biased genes were frequently transcribed from the Z chromosome, suggesting that dosage compensation in Z-linked genes does not occur or is incomplete at early embryonic stages. Our analysis has drawn a picture of a global landscape of sexually biased transcriptome during early B. mori embyogenesis and has suggested for the first time that most sexually biased embryonic transcripts depend on sex chromosomes.
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Affiliation(s)
- Munetaka Kawamoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hikaru Koga
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Keisuke Shoji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Sumio Sugano
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
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Xu J, Wang Y, Li Z, Ling L, Zeng B, James AA, Tan A, Huang Y. Transcription activator-like effector nuclease (TALEN)-mediated female-specific sterility in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2014; 23:800-7. [PMID: 25125145 PMCID: PMC4412852 DOI: 10.1111/imb.12125] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Engineering sex-specific sterility is critical for developing transgene-based sterile insect technology. Targeted genome engineering achieved by customized zinc-finger nuclease, transcription activator-like effector nuclease (TALEN) or clustered, regularly interspaced, short palindromic repeats/Cas9 systems has been exploited extensively in a variety of model organisms; however, screening mutated individuals without a detectable phenotype is still challenging. In addition, genetically recessive mutations only detectable in homozygotes make the experiments time-consuming. In the present study, we model a novel genetic system in the silkworm, Bombyx mori, that results in female-specific sterility by combining transgenesis with TALEN technologies. This system induces sex-specific sterility at a high efficiency by targeting the female-specific exon of the B. mori doublesex (Bmdsx) gene, which has sex-specific splicing isoforms regulating somatic sexual development. Transgenic animals co-expressing TALEN left and right arms targeting the female-specific Bmdsx exon resulted in somatic mutations and female mutants lost fecundity because of lack of egg storage and abnormal external genitalia. The wild-type sexual dimorphism of abdominal segment was not evident in mutant females. In contrast, there were no deleterious effects in mutant male moths. The current somatic TALEN technologies provide a promising approach for future insect functional genetics, thus providing the basis for the development of attractive genetic alternatives for insect population management.
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Affiliation(s)
- Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yueqiang Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiqian Li
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Ling
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baosheng Zeng
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anthony A. James
- Departments of Microbiology & Molecular Genetics and Molecular Biology & Biochemistry, University of California, Irvine, CA 92697-3900
| | - Anjiang Tan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- Correspondence: Y.P. Huang, ; Tel: 86-2154924046; Fax: 86- 2154924014; AJ.. Tan, ; Tel: 86-2154924046; Fax: 86- 2154924014
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- Correspondence: Y.P. Huang, ; Tel: 86-2154924046; Fax: 86- 2154924014; AJ.. Tan, ; Tel: 86-2154924046; Fax: 86- 2154924014
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A single female-specific piRNA is the primary determiner of sex in the silkworm. Nature 2014; 509:633-6. [PMID: 24828047 DOI: 10.1038/nature13315] [Citation(s) in RCA: 309] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 04/08/2014] [Indexed: 11/08/2022]
Abstract
The silkworm Bombyx mori uses a WZ sex determination system that is analogous to the one found in birds and some reptiles. In this system, males have two Z sex chromosomes, whereas females have Z and W sex chromosomes. The silkworm W chromosome has a dominant role in female determination, suggesting the existence of a dominant feminizing gene in this chromosome. However, the W chromosome is almost fully occupied by transposable element sequences, and no functional protein-coding gene has been identified so far. Female-enriched PIWI-interacting RNAs (piRNAs) are the only known transcripts that are produced from the sex-determining region of the W chromosome, but the function(s) of these piRNAs are unknown. Here we show that a W-chromosome-derived, female-specific piRNA is the feminizing factor of B. mori. This piRNA is produced from a piRNA precursor which we named Fem. Fem sequences were arranged in tandem in the sex-determining region of the W chromosome. Inhibition of Fem-derived piRNA-mediated signalling in female embryos led to the production of the male-specific splice variants of B. mori doublesex (Bmdsx), a gene which acts at the downstream end of the sex differentiation cascade. A target gene of Fem-derived piRNA was identified on the Z chromosome of B. mori. This gene, which we named Masc, encoded a CCCH-type zinc finger protein. We show that the silencing of Masc messenger RNA by Fem piRNA is required for the production of female-specific isoforms of Bmdsx in female embryos, and that Masc protein controls both dosage compensation and masculinization in male embryos. Our study characterizes a single small RNA that is responsible for primary sex determination in the WZ sex determination system.
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Suzuki MG, Ito H, Aoki F. Effects of RNAi-mediated knockdown of histone methyltransferases on the sex-specific mRNA expression of Imp in the silkworm Bombyx mori. Int J Mol Sci 2014; 15:6772-96. [PMID: 24758924 PMCID: PMC4013661 DOI: 10.3390/ijms15046772] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/25/2014] [Accepted: 04/10/2014] [Indexed: 12/11/2022] Open
Abstract
Sexual differentiation in Bombyx mori is controlled by sex-specific splicing of Bmdsx, which results in the omission of exons 3 and 4 in a male-specific manner. In B. mori, insulin-like growth factor II mRNA-binding protein (Imp) is a male-specific factor involved in male-specific splicing of Bmdsx. Male-specific Imp mRNA results from the male-specific inclusion of exon 8. To verify the link between histone methylation and alternative RNA processing in Imp, we examined the effects of RNAi-mediated knockdown of several histone methyltransferases on the sex-specific mRNA expression of Imp. As a result, male-specific expression of Imp mRNA was completely abolished when expression of the H3K79 methyltransferase DOT1L was repressed to <10% of that in control males. Chromatin immunoprecipitation-quantitative PCR analysis revealed a higher distribution of H3K79me2 in normal males than in normal females across Imp. RNA polymerase II (RNAP II) processivity assays indicated that RNAi knockdown of DOT1L in males caused a twofold decrease in RNAP II processivity compared to that in control males, with almost equivalent levels to those observed in normal females. Inhibition of RNAP II-mediated elongation in male cells repressed the male-specific splicing of Imp. Our data suggest the possibility that H3K79me2 accumulation along Imp is associated with the male-specific alternative processing of Imp mRNA that results from increased RNAP II processivity.
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Affiliation(s)
- Masataka G Suzuki
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
| | - Haruka Ito
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
| | - Fugaku Aoki
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
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Sexually dimorphic body color is regulated by sex-specific expression of yellow gene in ponerine ant, Diacamma sp. PLoS One 2014; 9:e92875. [PMID: 24667821 PMCID: PMC3965500 DOI: 10.1371/journal.pone.0092875] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 02/26/2014] [Indexed: 01/26/2023] Open
Abstract
Most hymenopteran species exhibit conspicuous sexual dimorphism due to ecological differences between the sexes. As hymenopteran genomes, under the haplodiploid genetic system, exhibit quantitative differences between sexes while remaining qualitatively identical, sexual phenotypes are assumed to be expressed through sex-specific gene usage. In the present study, the molecular basis for expression of sexual dimorphism in a queenless ant, Diacamma sp., which exhibits a distinct color dimorphism, was examined. Worker females of the species appear bluish-black, while winged males exhibit a yellowish-brown body color. Initially, observations of the pigmentation processes during pupal development revealed that black pigmentation was present in female pupae but not in males, suggesting that sex-specific melanin synthesis was responsible for the observed color dimorphism. Therefore, five orthologs of the genes involved in the insect melanin synthesis (yellow, ebony, tan, pale and dopa decarboxylase) were subcloned and their spatiotemporal expression patterns were examined using real-time quantitative RT-PCR. Of the genes examined, yellow, which plays a role in black melanin synthesis in insects, was expressed at higher levels in females than in males throughout the entire body during the pupal stage. RNA interference of yellow was then carried out in order to determine the gene function, and produced females with a more yellowish, brighter body color similar to that of males. It was concluded that transcriptional regulation of yellow was responsible for the sexual color dimorphism observed in this species.
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Gotoh H, Miyakawa H, Ishikawa A, Ishikawa Y, Sugime Y, Emlen DJ, Lavine LC, Miura T. Developmental link between sex and nutrition; doublesex regulates sex-specific mandible growth via juvenile hormone signaling in stag beetles. PLoS Genet 2014; 10:e1004098. [PMID: 24453990 PMCID: PMC3894178 DOI: 10.1371/journal.pgen.1004098] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 11/26/2013] [Indexed: 11/20/2022] Open
Abstract
Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters. Sexual dimorphisms such as the exaggerated antlers of deer, the enormous clawed chelae of crabs, and the horns and mandibles of beetles, are widespread across animal taxa and have fascinated biologists for centuries. Much recent work has uncovered the importance of the role of the sex-determination pathway in the expression of sexually dimorphic traits. However, critical interactions between this pathway and other growth regulatory mechanisms – for example, the physiological mechanisms involved in nutrition-dependent expression of these traits – are less well understood. In this study, we provide evidence of a developmental link between nutrition-sensitivity and sexual differentiation in the giant mandibles of the sexually dimorphic stag beetle, Cyclommatus metallifer. We examined the regulation and function of a key sex determination gene in animals, doublesex (dsx), and its interaction with juvenile hormone (JH), an important insect hormone known to regulate insect polyphenisms including the regulation of the disproportionate growth of male stag beetle mandibles. We found that Cmdsx changes mandibular responsiveness to JH in a sex-specific pattern. Based on these results, we hypothesize that sex-specific regulation of JH responsiveness is a developmental link between nutrition and sexual differentiation in stag beetles.
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Affiliation(s)
- Hiroki Gotoh
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
- Department of Entomology, Washington State University, Pullman, Washington, United States of America
| | - Hitoshi Miyakawa
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Asano Ishikawa
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
- Ecological Genetics Laboratory, Center for Frontier Research, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Yuki Ishikawa
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Yasuhiro Sugime
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Douglas J. Emlen
- Division of Biological Sciences, The University of Montana-Missoula, Missoula, Montana, United States of America
| | - Laura C. Lavine
- Department of Entomology, Washington State University, Pullman, Washington, United States of America
| | - Toru Miura
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
- * E-mail:
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Duan J, Xu H, Ma S, Guo H, Wang F, Zhang L, Zha X, Zhao P, Xia Q. Ectopic expression of the male BmDSX affects formation of the chitin plate in female Bombyx mori. Mol Reprod Dev 2014; 81:240-7. [PMID: 24420266 DOI: 10.1002/mrd.22290] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 12/03/2013] [Indexed: 12/22/2022]
Abstract
Mating structures are involved in successful copulation, intromission, and/or insemination. These structures enable tight coupling between external genitalia of two sexes. During Bombyx mori copulation, the double harpagones in the external genitalia of males clasp the female chitin plate, which is derived from the larval eighth abdominal segment; abnormal development of the female chitin plate affects copulation. We report that ERK phosphorylation (p-ERK) and expression of Abdominal-B (Abd-B) in the posterior abdomen of the female adult is lower than in the male. Ectopic expression of the male-specific spliced form of B. mori doublesex (Bmdsx(M)) in females, however, up-regulates Abd-B and spitz (spi) expression, increasing EGFR signaling activity, and thus forming an abnormal chitin plate and reduced female copulation. These findings indicate that Bmdsx affects the development of the eighth abdominal segment by regulating the activity of EGFR signaling and the expression of Abd-B, resulting in an extra eighth abdominal segment (A8) in males versus the loss of this segment in adult females.
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Affiliation(s)
- Jianping Duan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China; China-UK Nanyang Normal University-Rothamsted Research Joint Laboratory of Insect Biology, Henan Provincial Key Laboratory of Funiu Mountain Insect Biology, Nanyang Normal University, Nanyang, People's Republic of China
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