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Pospíšilová K, Van't Hof AE, Yoshido A, Kružíková R, Visser S, Zrzavá M, Bobryshava K, Dalíková M, Marec F. Masculinizer gene controls male sex determination in the codling moth, Cydia pomonella. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 160:103991. [PMID: 37536576 DOI: 10.1016/j.ibmb.2023.103991] [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: 05/24/2023] [Revised: 07/13/2023] [Accepted: 07/29/2023] [Indexed: 08/05/2023]
Abstract
The molecular mechanisms of sex determination in moths and butterflies (Lepidoptera) with female heterogamety (WZ/ZZ) are poorly understood, except in the silkworm Bombyx mori. However, the Masculinizer (Masc) gene that controls male development and dosage compensation in B. mori, appears to be conserved in Lepidoptera, as its masculinizing function was recently confirmed in several moth species. In this work, we investigated the role of the Masc gene in sex determination of the codling moth Cydia pomonella (Tortricidae), a globally important pest of pome fruits and walnuts. The gene structure of the C. pomonella Masc ortholog, CpMasc, is similar to B. mori Masc. However, unlike B. mori, we identified 14 splice variants of CpMasc in the available transcriptomes. Subsequent screening for sex specificity and genetic variation using publicly available data and RT-PCR revealed three male-specific splice variants. Then qPCR analysis of these variants revealed sex-biased expression showing a peak only in early male embryos. Knockdown of CpMasc by RNAi during early embryogenesis resulted in a shift from male-to female-specific splicing of the C. pomonella doublesex (Cpdsx) gene, its downstream effector, in ZZ embryos, leading to a strongly female-biased sex ratio. These data clearly demonstrate that CpMasc functions as a masculinizing gene in the sex-determining cascade of C. pomonella. Our study also showed that CpMasc transcripts are provided maternally, as they were detected in unfertilized eggs after oviposition and in mature eggs dissected from virgin females. This finding is unique, as maternal provision of mRNA has rarely been studied in Lepidoptera.
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Affiliation(s)
- Kristýna Pospíšilová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic.
| | - Arjen E Van't Hof
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic.
| | - Atsuo Yoshido
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic.
| | - Renata Kružíková
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic.
| | - Sander Visser
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic; School of Science and Engineering, University of Groningen, 9700 CC, Groningen, the Netherlands.
| | - Magda Zrzavá
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic.
| | - Kseniya Bobryshava
- Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic.
| | - Martina Dalíková
- Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic; Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA.
| | - František Marec
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, České Budějovice, Czech Republic.
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Hemolymph Ecdysteroid Titer Affects Maternal mRNAs during Bombyx mori Oogenesis. INSECTS 2021; 12:insects12110969. [PMID: 34821770 PMCID: PMC8622876 DOI: 10.3390/insects12110969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/11/2021] [Accepted: 10/25/2021] [Indexed: 01/02/2023]
Abstract
Simple Summary Both maternal genes and ecdysteroids play important roles during embryonic development. In this study, we aimed to characterize the dynamic landscape of maternal mRNAs and the relationship between maternal genes and ecdysteroids during silkworm oogenesis. For the first time, we determined the start of the accumulation of maternal mRNAs in the ovary at the wandering stage during the larval period. We detected the developmental expression profiles of each gene in the ovary or ovariole. We finally confirmed the role of 20-hydroxyecdysone in regulating maternal gene expression. Taken together, our findings expand the understanding of insect oogenesis and provide a perspective on the embryonic development of the silkworm. Abstract Silkworm larval–pupal metamorphosis and the first half of pupal–adult development occur during oogenesis from previtellogenesis to vitellogenesis and include two peaks of the hemolymph ecdysteroid titer. Moreover, a rise in 20-hydroxyecdysone titer in early pupae can trigger the first major transition from previtellogenesis to vitellogenesis in silkworm oogenesis. In this study, we first investigated the expression patterns of 66 maternal genes in the ovary at the wandering stage. We then examined the developmental expression profiles in six time-series samples of ovaries or ovarioles by reverse transcription–quantitative PCR. We found that the transcripts of 22 maternal genes were regulated by 20-hydroxyecdysone in the isolated abdomens of the pupae following a single injection of 20-hydroxyecdysone. This study is the first to determine the relationship between 20-hydroxyecdysone and maternal genes during silkworm oogenesis. These findings provide a basis for further research into the embryonic development of Bombyx mori.
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Xu PZ, Zhang MR, Wang XY, Wu YC. Precocious Metamorphosis of Silkworm Larvae Infected by BmNPV in the Latter Half of the Fifth Instar. Front Physiol 2021; 12:650972. [PMID: 34040541 PMCID: PMC8141865 DOI: 10.3389/fphys.2021.650972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
The mulberry silkworm (Bombyx mori) is a model organism, and BmNPV is a typical baculovirus. Together, these organisms form a useful model to investigate host-baculovirus interactions. Prothoracic glands (PGs) are also model organs, used to investigate the regulatory effect of synthetic ecdysone on insect growth and development. In this study, day-4 fifth instar silkworm larvae were infected with BmNPV. Wandering silkworms appeared in the infected groups 12 h earlier than in the control groups, and the ecdysone titer in infected larvae was significantly higher than that of the control larvae. We then used RNA sequencing (RNA-seq) to analyze silkworm PGs 48 h after BmNPV infection. We identified 15 differentially expressed genes (DEGs) that were classified as mainly being involved in metabolic processes and pathways. All 15 DEGs were expressed in the PGs, of which Novel01674, BmJing, and BmAryl were specifically expressed in the PGs. The transcripts of BmNGDN, BmTrypsin-1, BmACSS3, and BmJing were significantly increased, and BmPyd3, BmTitin, BmIGc2, Novel01674, and BmAryl were significantly decreased from 24 to 72 h in the PGs after BmNPV infection. The changes in the transcription of these nine genes were generally consistent with the transcriptome data. The upregulation of BmTrypsin-1 and BmACSS3 indicate that these DEGs may be involved in the maturation process in the latter half of the fifth instar of silkworm larvae. These findings further our understanding of silkworm larval development, the interaction between BmNPV infection and the host developmental response, and host-baculovirus interactions in general.
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Affiliation(s)
- Ping-Zhen Xu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Mei-Rong Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Xue-Yang Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Yang-Chun Wu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
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