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Tan KXY, Shigenobu S. In vivo interference of pea aphid endosymbiont Buchnera groEL gene by synthetic peptide nucleic acids. Sci Rep 2024; 14:5378. [PMID: 38438424 PMCID: PMC10912616 DOI: 10.1038/s41598-024-55179-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/21/2024] [Indexed: 03/06/2024] Open
Abstract
The unculturable nature of intracellular obligate symbionts presents a significant challenge for elucidating gene functionality, necessitating the development of gene manipulation techniques. One of the best-studied obligate symbioses is that between aphids and the bacterial endosymbiont Buchnera aphidicola. Given the extensive genome reduction observed in Buchnera, the remaining genes are crucial for understanding the host-symbiont relationship, but a lack of tools for manipulating gene function in the endosymbiont has significantly impeded the exploration of the molecular mechanisms underlying this mutualism. In this study, we introduced a novel gene manipulation technique employing synthetic single-stranded peptide nucleic acids (PNAs). We targeted the critical Buchnera groEL using specially designed antisense PNAs conjugated to an arginine-rich cell-penetrating peptide (CPP). Within 24 h of PNA administration via microinjection, we observed a significant reduction in groEL expression and Buchnera cell count. Notably, the interference of groEL led to profound morphological malformations in Buchnera, indicative of impaired cellular integrity. The gene knockdown technique developed in this study, involving the microinjection of CPP-conjugated antisense PNAs, provides a potent approach for in vivo gene manipulation of unculturable intracellular symbionts, offering valuable insights into their biology and interactions with hosts.
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Affiliation(s)
- Kathrine Xin Yee Tan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan
- Laboratory of Evolutionary Genomics, National Institute for Basic Biology, 38 Nishigonaka Myodaiji, Okazaki, Aichi, 444-8585, Japan
| | - Shuji Shigenobu
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
- Laboratory of Evolutionary Genomics, National Institute for Basic Biology, 38 Nishigonaka Myodaiji, Okazaki, Aichi, 444-8585, Japan.
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2
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Lin GW, Chung CY, Cook CE, Lin MD, Lee WC, Chang CC. Germline specification and axis determination in viviparous and oviparous pea aphids: conserved and divergent features. Dev Genes Evol 2022; 232:51-65. [PMID: 35678925 PMCID: PMC9329388 DOI: 10.1007/s00427-022-00690-7] [Citation(s) in RCA: 2] [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: 12/23/2021] [Accepted: 05/19/2022] [Indexed: 01/06/2023]
Abstract
Aphids are hemimetabolous insects that undergo incomplete metamorphosis without pupation. The annual life cycle of most aphids includes both an asexual (viviparous) and a sexual (oviparous) phase. Sexual reproduction only occurs once per year and is followed by many generations of asexual reproduction, during which aphids propagate exponentially with telescopic development. Here, we discuss the potential links between viviparous embryogenesis and derived developmental features in the pea aphid Acyrthosiphon pisum, particularly focusing on germline specification and axis determination, both of which are key events of early development in insects. We also discuss potential evolutionary paths through which both viviparous and oviparous females might have come to utilize maternal germ plasm to drive germline specification. This developmental strategy, as defined by germline markers, has not been reported in other hemimetabolous insects. In viviparous females, furthermore, we discuss whether molecules that in other insects characterize germ plasm, like Vasa, also participate in posterior determination and how the anterior localization of the hunchback orthologue Ap-hb establishes the anterior-posterior axis. We propose that the linked chain of developing oocytes and embryos within each ovariole and the special morphology of early embryos might have driven the formation of evolutionary novelties in germline specification and axis determination in the viviparous aphids. Moreover, based upon the finding that the endosymbiont Buchnera aphidicola is closely associated with germ cells throughout embryogenesis, we propose presumptive roles for B. aphidicola in aphid development, discussing how it might regulate germline migration in both reproductive modes of pea aphids. In summary, we expect that this review will shed light on viviparous as well as oviparous development in aphids.
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Affiliation(s)
- Gee-Way Lin
- Laboratory for Genomics and Development, College of Bio-Resources and Agriculture, Department of Entomology, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chen-Yo Chung
- Laboratory for Genomics and Development, College of Bio-Resources and Agriculture, Department of Entomology, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, NTU, Taipei, Taiwan
| | - Charles E Cook
- Laboratory for Genomics and Development, College of Bio-Resources and Agriculture, Department of Entomology, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Ming-Der Lin
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Wen-Chih Lee
- Research Center for Global SDGs Challenges, Office of Research and Development, Tzu Chi University, Hualien, Taiwan
| | - Chun-Che Chang
- Laboratory for Genomics and Development, College of Bio-Resources and Agriculture, Department of Entomology, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan.
- Research Center for Developmental Biology and Regenerative Medicine, NTU, Taipei, Taiwan.
- Institute of Biotechnology, College of Bio-Resources and Agriculture, NTU, Taipei, Taiwan.
- Genome and Systems Biology Degree Program, NTU, Taipei, Taiwan.
- International Graduate Program of Molecular Science and Technology, NTU, Taipei, Taiwan.
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3
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Nozaki T, Shigenobu S. Ploidy dynamics in aphid host cells harboring bacterial symbionts. Sci Rep 2022; 12:9111. [PMID: 35650254 PMCID: PMC9159990 DOI: 10.1038/s41598-022-12836-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 05/12/2022] [Indexed: 11/27/2022] Open
Abstract
Aphids have evolved bacteriocytes or symbiotic host cells that harbor the obligate mutualistic bacterium Buchnera aphidicola. Because of the large cell size (approximately 100 μm in diameter) of bacteriocytes and their pivotal role in nutritional symbiosis, researchers have considered that these cells are highly polyploid and assumed that bacteriocyte polyploidy may be essential for the symbiotic relationship between the aphid and the bacterium. However, little is known about the ploidy levels and dynamics of aphid bacteriocytes. Here, we quantitatively analyzed the ploidy levels in the bacteriocytes of the pea-aphid Acyrthosiphon pisum. Image-based fluorometry revealed the hyper polyploidy of the bacteriocytes ranging from 16- to 256-ploidy throughout the lifecycle. Bacteriocytes of adult parthenogenetic viviparous females were ranged between 64 and 128C DNA levels, while those of sexual morphs (oviparous females and males) were comprised of 64C, and 32–64C cells, respectively. During post-embryonic development of viviparous females, the ploidy level of bacteriocytes increased substantially, from 16 to 32C at birth to 128–256C in actively reproducing adults. These results suggest that the ploidy levels are dynamically regulated among phenotypes and during development. Our comprehensive and quantitative data provides a foundation for future studies to understand the functional roles and biological significance of the polyploidy of insect bacteriocytes.
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Affiliation(s)
- Tomonari Nozaki
- Laboratory of Evolutionary Genomics, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
| | - Shuji Shigenobu
- Laboratory of Evolutionary Genomics, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.,Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan
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4
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Otsuki A, Yoshizawa K, Akimoto SI. Phylogeography of the stonefly Kamimuria tibialis: multiple glacial refugia and sympatric occurrence of different lineages in the southern islands of Japan. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
To elucidate the effect of Pleistocene climatic fluctuations on the historical distribution and geographical genetic structure of temperate Japanese species, we performed phylogeographical and demographic analyses using mitochondrial gene sequences obtained from the stonefly species Kamimuria tibialis, sampled from four main islands of the Japanese Archipelago (i.e. Hokkaido, Honshu, Shikoku and Kyushu) and Tsushima Island. We detected three main clades with distinct geographical distributions, including the Tsushima, Kyushu and Hokkaido–Honshu–Shikoku phylogroups. These groups were estimated to have diverged from one another 0.54–2.02 Mya, suggesting they have undergone several glacial cycles in different refugia. Our results showed that during the glacial epochs and with a fall in sea-level, gene flow was limited among Tsushima and Kyushu, and among Hokkaido and Honshu, probably because the straits between these islands are deep. The population in Kyushu and Shikoku, the southernmost islands, exhibited high genetic diversity, with two distinct haplotype lineages occurring sympatrically. These results suggest that the population division into multiple refugia and the existence of stable southern refugia have contributed to the high genetic diversity of the species in this region.
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Affiliation(s)
- Akiko Otsuki
- Systematic Entomology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Kazunori Yoshizawa
- Systematic Entomology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Shin-Ichi Akimoto
- Systematic Entomology, Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
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Li Y, Akimoto SI. Self and non-self recognition affects clonal reproduction and competition in the pea aphid. Proc Biol Sci 2021; 288:20210787. [PMID: 34187194 PMCID: PMC8242831 DOI: 10.1098/rspb.2021.0787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 06/04/2021] [Indexed: 11/12/2022] Open
Abstract
The spatial interaction of clonal organisms is an unsolved but crucial topic in evolutionary biology. We evaluated the interactions between aphid clones using a colour mutant (yellow) and an original (green) clone. Colonies founded by two aphids of the same clone and mixed colonies, founded by a green aphid and a yellow aphid, were set up to observe population growth for 15 days. We confirmed positive competition effects, with mixed colonies increasing in size more rapidly than clonal colonies. In mixed colonies where reproduction started simultaneously, green aphids overwhelmed yellow aphids in number, and yellow aphids restrained reproduction. However, when yellow aphids started to reproduce earlier, they outnumbered the green aphids. To test whether aphids have the ability to control reproduction according to the densities of self and non-self clones, one yellow aphid or one antennae-excised yellow aphid was transferred into a highly dense green clone colony. Intact yellow aphids produced fewer nymphs in crowded green colonies, whereas the fecundity of antennae-excised aphids did not change. Thus, we conclude that aphid clones can discriminate between self and non-self clones, and can regulate their reproduction, depending on whether they are superior or inferior in number to their competitors.
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Affiliation(s)
- Yang Li
- Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
- College of Biology and Agriculture, Zunyi Normal University, Zunyi Guizhou 563006, People's Republic of China
| | - Shin-ichi Akimoto
- Department of Ecology and Systematics, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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Lee Y, Thieme T, Kim H. Complex evolution in Aphis gossypii group (Hemiptera: Aphididae), evidence of primary host shift and hybridization between sympatric species. PLoS One 2021; 16:e0245604. [PMID: 33539375 PMCID: PMC7861460 DOI: 10.1371/journal.pone.0245604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/05/2021] [Indexed: 11/17/2022] Open
Abstract
Aphids provide a good model system to understand the ecological speciation concept, since the majority of the species are host-specific, and they spend their entire lifecycle on certain groups of host plants. Aphid species that apparently have wide host plant ranges have often turned out to be complexes of host-specialized biotypes. Here we investigated the various host-associated populations of the two recently diverged species, Aphis gossypii and A. rhamnicola, having multiple primary hosts, to understand the complex evolution with host-associated speciation. Using mitochondrial DNA marker and nine microsatellite loci, we reconstructed the haplotype network, and analyzed the genetic structure and relationships. Approximate Bayesian computation was also used to infer the ancestral primary host and host-associated divergence, which resulted in Rhamnus being the most ancestral host for A. gossypii and A. rhamnicola. As a result, Aphis gossypii and A. rhamnicola do not randomly use their primary and secondary host plants; rather, certain biotypes use only some secondary and specific primary hosts. Some biotypes are possibly in a diverging state through specialization to specific primary hosts. Our results also indicate that a new heteroecious race can commonly be derived from the heteroecious ancestor, showing strong evidence of ecological specialization through a primary host shift in both A. gossypii and A. rhamnicola. Interestingly, A. gossypii and A. rhamnicola shared COI haplotypes with each other, thus there is a possibility of introgression by hybridization between them by cross-sharing same primary hosts. Our results contribute to a new perspective in the study of aphid evolution by identifying complex evolutionary trends in the gossypii sensu lato complex.
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Affiliation(s)
- Yerim Lee
- Animal Systematics Laboratory, Department of Biology, Kunsan National University, Gunsan, Republic of Korea
| | - Thomas Thieme
- BTL Bio-Test Labor GmbH Sagerheide, RG Phyto-Entomology, Gross Lüsewitz, Germany
| | - Hyojoong Kim
- Animal Systematics Laboratory, Department of Biology, Kunsan National University, Gunsan, Republic of Korea
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7
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Genetic and Epigenetic Changes during the Upward Expansion of Deyeuxia angustifolia Kom. in the Alpine Tundra of the Changbai Mountains, China. PLANTS 2021; 10:plants10020291. [PMID: 33546517 PMCID: PMC7913720 DOI: 10.3390/plants10020291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 11/17/2022]
Abstract
Ecological adaptation plays an important role in the process of plant expansion, and genetics and epigenetics are important in the process of plant adaptation. In this study, genetic and epigenetic analyses and soil properties were performed on D. angustifolia of 17 populations, which were selected in the tundra zone on the western slope of the Changbai Mountains. Our results showed that the levels of genetic and epigenetic diversity of D. angustifolia were relatively low, and the main variation occurred among different populations (amplified fragment length polymorphism (AFLP): 95%, methylation sensitive amplification polymorphism (MSAP): 87%). In addition, DNA methylation levels varied from 23.36% to 35.70%. Principal component analysis (PCA) results showed that soil properties of different populations were heterogeneous. Correlation analyses showed that soil moisture, pH and total nitrogen were significantly correlated with genetic diversity of D. angustifolia, and soil temperature and pH were closely related to epigenetic diversity. Simple Mantel tests and partial Mantel tests showed that genetic variation significantly correlated with habitat or geographical distance. However, the correlation between epigenetic variation and habitat or geographical distance was not significant. Our results showed that, in the case of low genetic variation and genetic diversity, epigenetic variation and DNA methylation may provide a basis for the adaptation of D. angustifolia.
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Tang M, Zhao W, Xing M, Zhao J, Jiang Z, You J, Ni B, Ni Y, Liu C, Li J, Chen X. Resource allocation strategies among vegetative growth, sexual reproduction, asexual reproduction and defense during growing season of Aconitum kusnezoffii Reichb. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:957-977. [PMID: 33180340 DOI: 10.1111/tpj.15080] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 09/28/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Natural plants must actively allocate their limited resources for survival and reproduction. Although vegetative growth, sexual reproduction, asexual reproduction and defense are all basic processes in the life cycle of plants, the strategies used to allocate resources between these processes are poorly understood. These processes are conspicuous in naturally grown Aconitum kusnezoffii Reichb., which makes it a suitable study subject. Here, the morphology, dry matter, total organic carbon, total nitrogen and aconitum alkaloid levels of shoot, principal root (PR) and lateral roots were measured throughout the growing season. Then, transcriptome and metabolite content analyses were performed. We found that vegetative growth began first. After vegetative growth ceased, sexual development began. Flower organ development was accompanied by increased photosynthesis and the PR consumed temporarily stored resources after flower formation. Asexual propagule development initiated earlier than sexual reproduction and kept accumulating resources after that. Development was slow before flower formation, mainly manifesting as increasing length; then, after flower formation it accelerated via enhanced material transport and accumulation. Defense compounds were maintained at low levels before flowering. In particular, the turnover of defense compounds was enhanced before and after flower bud emergence, providing resources for other processes. After flower formation, defense compounds were accumulated. The pattern found herein provides a vivid example for further studies on resource allocation strategies. The exciting finding that the PR, as a more direct storage site for photosynthate, is a buffer unit for resources, and that defense compounds can be reused for other processes, suggests a need to explore potential mechanisms.
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Affiliation(s)
- Mingze Tang
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Wei Zhao
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Ming Xing
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Jiaxin Zhao
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Zhang Jiang
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Jian You
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Biao Ni
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Yuanbo Ni
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Chengbai Liu
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Jiangnan Li
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
| | - Xia Chen
- National & Local United Engineering Laboratory for Chinese Herbal Medicine Breeding and Cultivation, School of Life Sciences, Jilin University, Changchun, Jilin Province, 130012, China
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Matsuda N, Numata H, Udaka H. Transcriptomic changes in the pea aphid, Acyrthosiphon pisum: Effects of the seasonal timer and photoperiod. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 36:100740. [PMID: 32906053 DOI: 10.1016/j.cbd.2020.100740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/28/2020] [Accepted: 08/27/2020] [Indexed: 12/11/2022]
Abstract
Many insect species use photoperiod as a cue for induction of seasonal responses, including seasonal polyphenism. Although most aphid species viviparously produce parthenogenetic and sexual morphs under long and short days, respectively, a seasonal timer suppresses the sexual morph production over several successive generations during a few months following hatching of a sexually produced diapause egg. To reveal the relative influences of photoperiod and the seasonal timer on the reproductive polyphenism at the gene expression level, we performed RNA sequencing-based transcriptome analyses in the pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae). Under short days, aphids with an expired seasonal timer showed a higher expression level in hundreds of genes than those with an operative seasonal timer. In contrast, aphids with an operative seasonal timer did not show upregulation in most of these genes. Functional annotations based on gene ontology showed that histone modifications and small non-coding RNA pathways were enriched in aphids with an expired seasonal timer under short-day conditions, suggesting that these epigenetic regulations on gene expression might be involved in a mechanism of maternal switching from the parthenogenetic to sexual morph production.
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Affiliation(s)
- Naoki Matsuda
- Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Hideharu Numata
- Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Hiroko Udaka
- Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
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Martel SI, Ossa CG, Simon J, Figueroa CC, Bozinovic F. Latitudinal trend in the reproductive mode of the pea aphid Acyrthosiphon pisum invading a wide climatic range. Ecol Evol 2020; 10:8289-8298. [PMID: 32788979 PMCID: PMC7417215 DOI: 10.1002/ece3.6536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 05/15/2020] [Accepted: 06/08/2020] [Indexed: 11/12/2022] Open
Abstract
The maintenance of sexuality is a puzzling phenomenon in evolutionary biology. Many universal hypotheses have been proposed to explain the prevalence of sex despite its costs, but it has been hypothesized that sex could be also retained by lineage-specific mechanisms that would confer some short-term advantage. Aphids are good models to study the maintenance of sex because they exhibit coexistence of both sexual and asexual populations within the same species and because they invade a large variety of ecosystems. Sex in aphids is thought to be maintained because only sexually produced eggs can persist in cold climates, but whether sex is obligate or facultative depending on climatic conditions remains to be elucidated. In this study, we have inferred the reproductive mode of introduced populations of the pea aphid Acyrthosiphon pisum in Chile along a climatic gradient using phenotypic assays and genetic-based criteria to test the ecological short-term advantage of sex in cold environments. Our results showed a latitudinal trend in the reproductive mode of Chilean pea aphid population from obligate parthenogenesis in the north to an intermediate life cycle producing both parthenogenetic and sexual progeny in the southernmost locality, where harsh winters are usual. These findings are congruent with the hypothesis of the ecological short-term advantage of sex in aphids.
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Affiliation(s)
- Sebastián I. Martel
- Departamento de EcologíaFacultad de Ciencias BiológicasCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiago de ChileChile
| | - Carmen G. Ossa
- Instituto de BiologíaFacultad de CienciasUniversidad de ValparaísoValparaísoChile
| | | | - Christian C. Figueroa
- Instituto de Ciencias BiológicasCenter for Molecular and Functional Ecology in Agroecosystems (CEMF)Universidad de TalcaTalcaChile
| | - Francisco Bozinovic
- Departamento de EcologíaFacultad de Ciencias BiológicasCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiago de ChileChile
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11
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Wang D, Shi X, Liu D, Yang Y, Shang Z. Genetic Divergence of Two Sitobion avenae Biotypes on Barley and Wheat in China. INSECTS 2020; 11:insects11020117. [PMID: 32054103 PMCID: PMC7073604 DOI: 10.3390/insects11020117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 11/16/2022]
Abstract
Host plant affinity and geographic distance can play critical roles in the genetic divergence of insect herbivores and evolution of insect biotypes, but their relative importance in the divergence of insect populations is still poorly understood. We used microsatellite markers to test the effects of host plant species and geographic distance on divergence of two biotypes of the English grain aphid, Sitobion avenae (Fabricius). We found that clones of S. avenae from western provinces (i.e., Xinjiang, Gansu, Qinghai and Shaanxi) had significantly higher genetic diversity than those from eastern provinces (i.e., Anhui, Henan, Hubei, Zhejiang and Jiangsu), suggesting their differentiation between both areas. Based on genetic diversity and distance estimates, biotype 1 clones of eastern provinces showed high genetic divergence from those of western provinces in many cases. Western clones of S. avenae also showed higher genetic divergence among themselves than eastern clones. The Mantel test identified a significant isolation-by-distance (IBD) effect among different geographic populations of S. avenae, providing additional evidence for a critical role of geography in the genetic structure of both S. avenae biotypes. Genetic differentiation (i.e., FST) between the two biotypes was low in all provinces except Shaanxi. Surprisingly, in our analyses of molecular variance, non-significant genetic differentiation between both biotypes or between barley and wheat clones of S. avenae was identified, showing little contribution of host-plant associated differentiation to the divergence of both biotypes in this aphid. Thus, it is highly likely that the divergence of the two S. avenae biotypes involved more geographic isolation and selection of some form than host plant affinity. Our study can provide insights into understanding of genetic structure of insect populations and the divergence of insect biotypes.
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Affiliation(s)
- Da Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, Shaanxi, China; (D.W.); (Y.Y.); (Z.S.)
- College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xiaoqin Shi
- Department of Foreign Languages, Northwest A&F University, Yangling 712100, Shaanxi, China;
| | - Deguang Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, Shaanxi, China; (D.W.); (Y.Y.); (Z.S.)
- College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
- Correspondence:
| | - Yujing Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, Shaanxi, China; (D.W.); (Y.Y.); (Z.S.)
- College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Zheming Shang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, Shaanxi, China; (D.W.); (Y.Y.); (Z.S.)
- College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
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12
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Murano K, Ogawa K, Kaji T, Miura T. Pheromone gland development and monoterpenoid synthesis specific to oviparous females in the pea aphid. ZOOLOGICAL LETTERS 2018; 4:9. [PMID: 29780614 PMCID: PMC5946545 DOI: 10.1186/s40851-018-0092-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/03/2018] [Indexed: 05/31/2023]
Abstract
BACKGROUND Aphids display "cyclic parthenogenesis," in which parthenogenetically and sexually reproducing morphs seasonally alternate in the aphid annual life cycles. There are various characteristics that differ between asexual viviparous and sexual oviparous females. In oviparous females, swollen cuticular structures (~ 10 μm in diameter), called "scent plaques," are scattered on the surface of hind tibias, and secrete monoterpenoid sex pheromones. However, the developmental processes of the pheromone glands and the biosynthetic pathways of monoterpenoid pheromones have yet to be elucidated. RESULTS Comparisons of the developmental processes that form hind tibias between sexual and parthenogenetic females revealed that, in sexual females, the epithelial tissues in proximal parts of hind tibias become columnar in fourth instar nymphs, and circular pheromone glands with Class 1 gland cells appear in adults, although they do not appear in parthenogenetic females. Furthermore, by comparing the expression levels of genes involved in the mevalonate pathway, which is required for monoterpenoid synthesis, we show that genes that encode the downstream enzymes in the pathway are highly expressed in hind tibias of sexual females. CONCLUSION Glandular tissues of scent plaque are differentiated from the fourth instar in sexual females, while parthenogenetic females lack the glandular cells. Only the downstream steps of the mevalonate pathway appear to occur in scent plaques on hind tibias of sexual females, although the upstream steps may occur somewhere in other body parts.
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Affiliation(s)
- Koki Murano
- Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan
| | - Kota Ogawa
- Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan
- Laboratory of Functional Genomics, National Institute for Basic Biology, Okazaki, Aichi 444-8585 Japan
| | - Tomonari Kaji
- Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan
- Bamfield Marine Science Centre, 100 Pachena Rd, Bamfield, British Columbia V0R 1B0 Canada
| | - Toru Miura
- Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810 Japan
- Misaki Marine Biological Station, School of Science, The University of Tokyo, 1024 Koajiro, Misaki, Miura, Kanagawa 238-0225 Japan
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Matsuda N, Kanbe T, Akimoto SI, Numata H. Transgenerational seasonal timer for suppression of sexual morph production in the pea aphid, Acyrthosiphon pisum. JOURNAL OF INSECT PHYSIOLOGY 2017; 101:1-6. [PMID: 28610748 DOI: 10.1016/j.jinsphys.2017.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 06/09/2017] [Accepted: 06/09/2017] [Indexed: 06/07/2023]
Abstract
Many aphid species switch reproductive modes seasonally, with the sexual generations appearing in autumn. Sexual generations are induced by short days. It has been reported that the appearance of sexual morphs is suppressed by a transgenerational factor (a seasonal timer) over several generations after hatching from overwintered eggs. The present study examined whether the seasonal timer measures the number of days from hatching or the number of generations from hatching using the pea aphid, Acyrthosiphon pisum Harris (Homoptera: Aphididae). Effects of temperature and photoperiod on the seasonal timer were also examined by successive rearing. The ability to produce sexual morphs was strongly suppressed in stem mothers (the foundress generation), and gradually recovered over successive generations produced during a few months. The duration for which the seasonal timer could function depended on the number of days from hatching and temperature, but not on photoperiod or the number of generations from hatching. We thus showed in a single study that the seasonal timer of the pea aphid has all the physiological characteristics shown in separate studies in different aphid species.
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Affiliation(s)
- Naoki Matsuda
- Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Takashi Kanbe
- Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
| | - Shin-Ichi Akimoto
- Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
| | - Hideharu Numata
- Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
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Yuan G, Wan Y, Li X, He B, Zhang Y, Xu B, Wang S, Xie W, Zhou X, Wu Q. Development of Near-Isogenic Lines in a Parthenogenetically Reproduced Thrips Species, Frankliniella occidentalis. Front Physiol 2017; 8:130. [PMID: 28348528 PMCID: PMC5346592 DOI: 10.3389/fphys.2017.00130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/20/2017] [Indexed: 12/14/2022] Open
Abstract
Although near-isogenic lines (NILs) can standardize genetic backgrounds among individuals, it has never been applied in parthenogenetically reproduced animals. Here, through multiple rounds of backcrossing and spinosad screening, we generated spinosad resistant NILs in the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), with a haplo-diploid reproduction system. The resultant F. occidentalis NIL-R strain maintained a resistance ratio over 30,000-fold, which was comparable to its parental resistant strain, Spin-R. More importantly, F. occidentalis NIL-R shared 98.90% genetic similarity with its susceptible parental strain Ivf03. By developing this toolset, we are able to segregate individual resistance and facilitate the mechanistic study of insecticide resistances in phloem-feeding arthropods, a group of devastating pest species reproducing sexually as well as asexually.
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Affiliation(s)
- Guangdi Yuan
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Yanran Wan
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Xiaoyu Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Bingqing He
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Youjun Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Baoyun Xu
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Shaoli Wang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Wen Xie
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
| | - Xuguo Zhou
- Department of Entomology, University of Kentucky Lexington, KY, USA
| | - Qingjun Wu
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China
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15
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Peng X, Qiao X, Chen M. Responses of holocyclic and anholocyclic Rhopalosiphum padi populations to low-temperature and short-photoperiod induction. Ecol Evol 2017; 7:1030-1042. [PMID: 28303175 PMCID: PMC5306053 DOI: 10.1002/ece3.2720] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 12/02/2016] [Accepted: 12/18/2016] [Indexed: 11/21/2022] Open
Abstract
The different life cycles of aphid species make these organisms good models for studying the short‐term consequences of sex. The bird cherry‐oat aphid Rhopalosiphum padi has a wide geographic distribution and correspondingly different life cycles. In this study, the life cycles of R. padi collected from six different regions in China were characterized experimentally by comparing the responses of holocyclic and anholocyclic populations to low‐temperature and short‐photoperiod induction. Clones collected from Chuzhou, Taian, and Taigu consistently reproduced via obligate parthenogenesis, whereas clones from Hami and Baicheng were holocyclic in their response, and those from Lanzhou were both holocyclic and anholocyclic. Prolonged exposure to low temperature and a short photoperiod (LS) had negative effects on the offspring of anholocyclic aphids with regard to adult lifespan, total longevity, and fecundity compared with aphids maintained at a normal temperature and a long photoperiod (NL). Holocyclic LS R. padi had longer developmental times at all nymph stages, a shorter adult lifespan, shorter total longevity, and a lower fecundity than NL counterparts. The adult prereproduction period of gynoparae was significantly longer than that of virginoparae, and the total longevity of gynoparae was significantly shorter than that of virginoparae. Moreover, the net reproductive and gross reproduction rates, as well as the total fecundity, were roughly fivefold higher in virginoparae than in gynoparae, indicating that there is the short‐term cost of sex. When maintained on their secondary host (Triticum aestivum), gynoparae, males, and oviparae produced by holocyclic populations could survive, and gynoparae produced oviparae. However, under NL conditions, oviparae could not produce overwintering eggs on the secondary host, whereas a few overwintering eggs were generated by oviparae under LS conditions. Taken together, these results illuminate the complexity of insect responses and contribute to a complete understanding of the aphid life cycle and its evolution.
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Affiliation(s)
- Xiong Peng
- Northwest A&F UniversityYanglingShaanxi ProvinceChina
| | - Xianfeng Qiao
- Northwest A&F UniversityYanglingShaanxi ProvinceChina
| | - Maohua Chen
- Northwest A&F UniversityYanglingShaanxi ProvinceChina
- State Key Laboratory of Crop Stress Biology for Arid AreasKey Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of AgricultureYanglingShaanxi ProvinceChina
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Kim H, Hoelmer KA, Lee S. Population genetics of the soybean aphid in North America and East Asia: test for introduction between native and introduced populations. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1299-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Effects of complex life cycles on genetic diversity: cyclical parthenogenesis. Heredity (Edinb) 2016; 117:336-347. [PMID: 27436524 DOI: 10.1038/hdy.2016.52] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 06/02/2016] [Accepted: 06/08/2016] [Indexed: 11/08/2022] Open
Abstract
Neutral patterns of population genetic diversity in species with complex life cycles are difficult to anticipate. Cyclical parthenogenesis (CP), in which organisms undergo several rounds of clonal reproduction followed by a sexual event, is one such life cycle. Many species, including crop pests (aphids), human parasites (trematodes) or models used in evolutionary science (Daphnia), are cyclical parthenogens. It is therefore crucial to understand the impact of such a life cycle on neutral genetic diversity. In this paper, we describe distributions of genetic diversity under conditions of CP with various clonal phase lengths. Using a Markov chain model of CP for a single locus and individual-based simulations for two loci, our analysis first demonstrates that strong departures from full sexuality are observed after only a few generations of clonality. The convergence towards predictions made under conditions of full clonality during the clonal phase depends on the balance between mutations and genetic drift. Second, the sexual event of CP usually resets the genetic diversity at a single locus towards predictions made under full sexuality. However, this single recombination event is insufficient to reshuffle gametic phases towards full-sexuality predictions. Finally, for similar levels of clonality, CP and acyclic partial clonality (wherein a fixed proportion of individuals are clonally produced within each generation) differentially affect the distribution of genetic diversity. Overall, this work provides solid predictions of neutral genetic diversity that may serve as a null model in detecting the action of common evolutionary or demographic processes in cyclical parthenogens (for example, selection or bottlenecks).
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18
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Chen YY, Lin CW, Huang WF, Chang JR, Su IJ, Hsu CH, Cheng HY, Hsu SC, Dou HY. Recombinant bacille Calmette-Guerin coexpressing Ag85b, CFP10, and interleukin-12 elicits effective protection against Mycobacterium tuberculosis. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2014; 50:90-96. [PMID: 25732698 DOI: 10.1016/j.jmii.2014.11.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/11/2014] [Accepted: 11/29/2014] [Indexed: 01/10/2023]
Abstract
BACKGROUND The tuberculosis (TB) pandemic remains a leading cause of human morbidity and mortality, despite widespread use of the only licensed anti-TB vaccine, bacille Calmette-Guerin (BCG). The protective efficacy of BCG in preventing pulmonary TB is highly variable; therefore, an effective new vaccine is urgently required. METHODS In the present study, we assessed the ability of novel recombinant BCG vaccine (rBCG) against Mycobacterium tuberculosis by using modern immunological methods. RESULTS Enzyme-linked immunospot assays demonstrated that the rBCG vaccine, which coexpresses two mycobacterial antigens (Ag85B and CFP10) and human interleukin (IL)-12 (rBCG2) elicits greater interferon-γ (IFN-γ) release in the mouse lung and spleen, compared to the parental BCG. In addition, rBCG2 triggers a Th1-polarized response. Our results also showed that rBCG2 vaccination significantly limits M. tuberculosis H37Rv multiplication in macrophages. The rBCG2 vaccine surprisingly induces significantly higher tumor necrosis factor-α (TNF-α) production by peripheral blood mononuclear cells that were exposed to a nonmycobacterial stimulus, compared to the parental BCG. CONCLUSION In this study, we demonstrated that the novel rBCG2 vaccine may be a promising candidate vaccine against M. tuberculosis infection.
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MESH Headings
- Acyltransferases/administration & dosage
- Acyltransferases/genetics
- Acyltransferases/immunology
- Adjuvants, Immunologic/administration & dosage
- Adjuvants, Immunologic/genetics
- Animals
- Antigens, Bacterial/administration & dosage
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Bacterial Proteins/administration & dosage
- Bacterial Proteins/genetics
- Bacterial Proteins/immunology
- Enzyme-Linked Immunospot Assay
- Female
- Humans
- Interferon-gamma/metabolism
- Interleukin-12/administration & dosage
- Interleukin-12/genetics
- Leukocytes, Mononuclear/immunology
- Lung/immunology
- Macrophages/immunology
- Macrophages/microbiology
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mycobacterium bovis/genetics
- Mycobacterium bovis/immunology
- Mycobacterium tuberculosis/growth & development
- Mycobacterium tuberculosis/immunology
- Spleen/immunology
- Th1 Cells/immunology
- Tuberculosis/prevention & control
- Tuberculosis Vaccines/administration & dosage
- Tuberculosis Vaccines/genetics
- Tuberculosis Vaccines/immunology
- Tumor Necrosis Factor-alpha/metabolism
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Yih-Yuan Chen
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Chih-Wei Lin
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Wei-Feng Huang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Jia-Ru Chang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Ih-Jen Su
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Chih-Hao Hsu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Han-Yin Cheng
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Shu-Ching Hsu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Horng-Yunn Dou
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
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19
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Lin GW, Cook CE, Miura T, Chang CC. Posterior localization of ApVas1 positions the preformed germ plasm in the sexual oviparous pea aphid Acyrthosiphon pisum. EvoDevo 2014; 5:18. [PMID: 24855557 PMCID: PMC4030528 DOI: 10.1186/2041-9139-5-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 04/23/2014] [Indexed: 12/19/2022] Open
Abstract
Background Germline specification in some animals is driven by the maternally inherited germ plasm during early embryogenesis (inheritance mode), whereas in others it is induced by signals from neighboring cells in mid or late development (induction mode). In the Metazoa, the induction mode appears as a more prevalent and ancestral condition; the inheritance mode is therefore derived. However, regarding germline specification in organisms with asexual and sexual reproduction it has not been clear whether both strategies are used, one for each reproductive phase, or if just one strategy is used for both phases. Previously we have demonstrated that specification of germ cells in the asexual viviparous pea aphid depends on a preformed germ plasm. In this study, we extended this work to investigate how germ cells were specified in the sexual oviparous embryos, aiming to understand whether or not developmental plasticity of germline specification exists in the pea aphid. Results We employed Apvas1, a Drosophila vasa ortholog in the pea aphid, as a germline marker to examine whether germ plasm is preformed during oviparous development, as has already been seen in the viviparous embryos. During oogenesis, Apvas1 mRNA and ApVas1 protein were both evenly distributed. After fertilization, uniform expression of Apvas1 remained in the egg but posterior localization of ApVas1 occurred from the fifth nuclear cycle onward. Posterior co-localization of Apvas1/ApVas1 was first identified in the syncytial blastoderm undergoing cellularization, and later we could detect specific expression of Apvas1/ApVas1 in the morphologically identifiable germ cells of mature embryos. This suggests that Apvas1/ApVas1-positive cells are primordial germ cells and posterior localization of ApVas1 prior to cellularization positions the preformed germ plasm. Conclusions We conclude that both asexual and sexual pea aphids rely on the preformed germ plasm to specify germ cells and that developmental plasticity of germline specification, unlike axis patterning, occurs in neither of the two aphid reproductive phases. Consequently, the maternal inheritance mode implicated by a preformed germ plasm in the oviparous pea aphid becomes a non-canonical case in the Hemimetabola, where so far the zygotic induction mode prevails in most other studied insects.
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Affiliation(s)
- Gee-Way Lin
- Laboratory for Genetics and Development, Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, No. 27, Lane 113, Roosevelt Road, Sec. 4, Taipei 106, Taiwan ; Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, N10 W5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Charles E Cook
- EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Toru Miura
- Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, N10 W5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Chun-Che Chang
- Laboratory for Genetics and Development, Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, No. 27, Lane 113, Roosevelt Road, Sec. 4, Taipei 106, Taiwan ; Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei 100, Taiwan ; Genome and Systems Biology Degree Program, National Taiwan University, Taipei 106, Taiwan
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20
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Piffaretti J, Clamens AL, Vanlerberghe-Masutti F, Gupta RK, Call E, Halbert S, Jousselin E. Regular or covert sex defines two lineages and worldwide superclones within the leaf-curl plum aphid (Brachycaudus helichrysi, Kaltenbach). Mol Ecol 2013; 22:3916-32. [PMID: 23786407 DOI: 10.1111/mec.12371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/25/2013] [Accepted: 04/25/2013] [Indexed: 10/26/2022]
Abstract
Asexual reproduction occurs widely in plants and animals, particularly in insects. Aphid species usually reproduce by cyclic parthenogenesis, but many species include obligate asexual lineages. We recently showed that the leaf-curl plum aphid, Brachycaudus helichrysi, actually encompasses two lineages, B. helichrysi H1 and H2. Ecological data suggest that these lineages have different life cycles. We conducted a large population genetics study, based on 14 microsatellite loci, to infer their respective life cycles and investigate their population structure and geographical distribution. Brachycaudus helichrysi H1 displayed the genetic signature of cyclical parthenogenesis, using plum trees as primary hosts for sexual reproduction, as classically described for B. helichrysi. This global survey showed that the Central Asian population of H1 was clearly differentiated from American-European populations. By contrast, B. helichrysi H2 displayed the typical signature of obligate asexual reproduction. H2 encompassed at least eight highly successful genotypes or superclones. This lack of ability to undergo sexual reproduction was confirmed for one of the superclones by sex induction experiments. We found only one B. helichrysi H2 population that underwent sexual reproduction, which was collected from peach trees, in Northern India. Our results confirm that H1 and H2 have different life cycles. Brachycaudus helichrysi H1 is clearly heteroecious using plum trees as primary hosts, while B. helichrysi H2 encompasses several anholocyclic lineages, and some heteroecious populations that until now have only been found associated with peach trees as primary hosts. We discuss implications of these findings for the pest status of B. helichrysi lineages.
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Affiliation(s)
- J Piffaretti
- INRA - UMR 1062 CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Centre de Biologie pour la Gestion des Populations, Campus International de Baillarguet CS 30 016, Montferrier-sur-Lez, F-34 988, France.
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Ivens ABF, Kronauer DJC, Pen I, Weissing FJ, Boomsma JJ. Reproduction and dispersal in an ant-associated root aphid community. Mol Ecol 2012; 21:4257-69. [PMID: 22804757 DOI: 10.1111/j.1365-294x.2012.05701.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Clonal organisms with occasional sex are important for our general understanding of the costs and benefits that maintain sexual reproduction. Cyclically parthenogenetic aphids are highly variable in their frequency of sexual reproduction. However, studies have mostly focused on free-living aphids above ground, whereas dispersal constraints and dependence on ant-tending may differentially affect the costs and benefits of sex in subterranean aphids. Here, we studied reproductive mode and dispersal in a community of root aphids that are obligately associated with the ant Lasius flavus. We assessed the genetic population structure of four species (Geoica utricularia, Tetraneura ulmi, Forda marginata and Forda formicaria) in a Dutch population and found that all species reproduce predominantly if not exclusively asexually, so that populations consist of multiple clonal lineages. We show that population viscosity is high and winged aphids rare, consistent with infrequent horizontal transmission between ant host colonies. The absence of the primary host shrub (Pistacia) may explain the absence of sex in three of the studied species, but elm trees (Ulmus) that are primary hosts of the fourth species (T. ulmi) occurred within a few km of the study population. We discuss the extent to which obligate ant-tending and absence of primary hosts may have affected selection for permanent parthenogenesis, and we highlight the need for further study of these aphids in Southern Europe where primary hosts may occur close to L. flavus populations, so that all four root aphid species would have realistic opportunities for completing their sexual life cycle.
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Affiliation(s)
- A B F Ivens
- Theoretical Biology, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
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22
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Barbuti R, Mautner S, Carnevale G, Milazzo P, Rama A, Sturmbauer C. Population dynamics with a mixed type of sexual and asexual reproduction in a fluctuating environment. BMC Evol Biol 2012; 12:49. [PMID: 22489797 PMCID: PMC3353185 DOI: 10.1186/1471-2148-12-49] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 04/10/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Carassius gibelio, a cyprinid fish from Eurasia, has the ability to reproduce both sexually and asexually. This fish is also known as an invasive species which colonized almost all continental Europe, most likely originating from Asia and Eastern Europe. Populations of both sexually and asexually reproducing individuals exist in sympatry. In this study we try to elucidate the advantages of such a mixed type of reproduction. We investigate the dynamics of two sympatric populations with sexual and asexual reproduction in a periodically fluctuating environment. We define an individual-based computational model in which genotypes are represented by L loci, and the environment is composed of L resources for which the two populations compete. RESULTS Our model demonstrates advantageous population dynamics where the optimal percentage of asexual reproduction depends on selection strength, on the number of selected loci and on the timescale of environmental fluctuations. We show that the sexual reproduction is necessary for "generating" fit genotypes, while the asexual reproduction is suitable for "amplifying" them. The simulations show that the optimal percentage of asexual reproduction increases with the length of the environment stability period and decrease with the strength of the selection and the number of loci. CONCLUSIONS In this paper we addressed the advantages of a mixed type of sexual and asexual reproduction in a changing environment and explored the idea that a species that is able to adapt itself to environmental fluctuation can easily colonize a new habitat. Our results could provide a possible explanation for the rapid and efficient invasion of species with a variable ratio of sexual and asexual reproduction such as Carassius gibelio.
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Affiliation(s)
- Roberto Barbuti
- Dipartimento di Informatica, Università di Pisa, Pisa, Italy
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23
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Allen DE, Lynch M. The effect of variable frequency of sexual reproduction on the genetic structure of natural populations of a cyclical parthenogen. Evolution 2012; 66:919-926. [PMID: 22380451 PMCID: PMC4521562 DOI: 10.1111/j.1558-5646.2011.01488.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclical parthenogens are a valuable system in which to empirically test theoretical predictions as to the genetic consequences of sexual reproduction in natural populations, particularly if the frequency of sexual relative to asexual reproduction can be quantified. In this study, we used a series of lake populations of the cyclical parthenogen, Daphnia pulicaria, that vary consistently in their investment in sexual reproduction, to address the questions of whether the ecological variation in investment in sex is detectable at the genetic level, and if so, whether the genetic patterns seen are consistent with theoretical predictions. We show that there is variation in the genetic structure of these populations in a manner consistent with their investment in sexual reproduction. Populations engaging in a high frequency of sex were in Hardy-Weinberg and gametic phase equilibrium, and showed little genotypic differentiation across sampled years. In contrast, populations with a lower frequency of sex deviated widely from equilibrium, had reduced multilocus clonal diversity, and showed significant temporal genotypic deviation.
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Affiliation(s)
- Desiree E Allen
- Department of Biology, Indiana University, Bloomington, Indiana 47405 E-mail:
| | - Michael Lynch
- Department of Biology, Indiana University, Bloomington, Indiana 47405 E-mail:
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Ishikawa A, Ogawa K, Gotoh H, Walsh TK, Tagu D, Brisson JA, Rispe C, Jaubert-Possamai S, Kanbe T, Tsubota T, Shiotsuki T, Miura T. Juvenile hormone titre and related gene expression during the change of reproductive modes in the pea aphid. INSECT MOLECULAR BIOLOGY 2012; 21:49-60. [PMID: 21988597 DOI: 10.1111/j.1365-2583.2011.01111.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Most aphids show reproductive polyphenism, i.e. they alternate their reproductive modes from parthenogenesis to sexual reproduction in response to short photoperiods. Although juvenile hormone (JH) has been considered a likely candidate for regulating the transition from asexual to sexual reproduction after photoperiod sensing, there are few studies investigating the direct relationship between JH titres and the reproductive-mode change. In addition, the sequencing of the pea aphid genome has allowed identification of the genes involved in the JH pathway, which in turn allows us to examine their expression levels in relation to the reproductive-mode change. Using liquid chromatography-mass spectrometry in the pea aphid, JHIII titre was shown to be lower in aphids producing sexual morphs under short-day conditions than in aphids producing parthenogenetic morphs under long-day conditions. The expression levels of genes upstream and downstream of JH action were quantified by real-time quantitative reverse-transcription-PCR across the reproductive-mode change. The expression level of JH esterase, which is responsible for JH degradation, was significantly higher in aphids reared under short-day conditions. This suggests that the upregulation of the JH degradation pathway may be responsible for the lower JHIII titre in aphids exposed to short-days, leading to the production of sexual morphs.
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Affiliation(s)
- A Ishikawa
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan
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25
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Thomas MA, Schötz EM. SAPling: a Scan-Add-Print barcoding database system to label and track asexual organisms. ACTA ACUST UNITED AC 2012; 214:3518-23. [PMID: 21993779 DOI: 10.1242/jeb.059048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have developed a 'Scan-Add-Print' database system, SAPling, to track and monitor asexually reproducing organisms. Using barcodes to uniquely identify each animal, we can record information on the life of the individual in a computerized database containing its entire family tree. SAPling has enabled us to carry out large-scale population dynamics experiments with thousands of planarians and keep track of each individual. The database stores information such as family connections, birth date, division date and generation. We show that SAPling can be easily adapted to other asexually reproducing organisms and has a strong potential for use in large-scale and/or long-term population and senescence studies as well as studies of clonal diversity. The software is platform-independent, designed for reliability and ease of use, and provided open source from our webpage to allow project-specific customization.
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Affiliation(s)
- Michael A Thomas
- 170 Carl Icahn Laboratory, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
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26
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Sandrock C, Razmjou J, Vorburger C. Climate effects on life cycle variation and population genetic architecture of the black bean aphid, Aphis fabae. Mol Ecol 2011; 20:4165-81. [PMID: 21883588 DOI: 10.1111/j.1365-294x.2011.05242.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Aphid species may exhibit different reproductive modes ranging from cyclical to obligate parthenogenesis. The distribution of life cycle variation in aphids is generally determined by ecological forces, mainly climate, because only sexually produced diapausing eggs can survive harsh winters or periods of absence of suitable host plants. Aphids are thus interesting models to investigate intrinsic and environmental factors shaping the competition among sexual and asexual lineages. We conducted a Europe-wide sampling of black bean aphids, Aphis fabae, and combined population genetic analyses based on microsatellite data with an experimental determination of life cycle strategies. Aphids were collected from broad beans (Vicia faba) as well as some Chenopodiaceae, but we detected no genetic differentiation between aphids from different host plants. Consistent with model predictions, life cycle variation was related to climate, with aphids from areas with cold winters investing more in sexual reproduction than aphids from areas with mild winters. Accordingly, only populations from mild areas exhibited a clear genetic signature of clonal reproduction. These differences arise despite substantial gene flow over large distances, which was evident from a very low geographic population structure and a lack of isolation-by-distance among 18 sites across distances of more than 1000 km. There was virtually no genetic differentiation between aphids with different reproductive modes, suggesting that new asexual lineages are formed continuously. Indeed, a surprising number of A. fabae genotypes even from colder climates produced some parthenogenetic offspring under simulated winter conditions. From this we predict that a shift to predominantly asexual reproduction could take place rapidly under climate warming.
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Affiliation(s)
- Christoph Sandrock
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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27
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Harrison JS, Mondor EB. Evidence for an invasive aphid "superclone": extremely low genetic diversity in Oleander aphid (Aphis nerii) populations in the southern United States. PLoS One 2011; 6:e17524. [PMID: 21408073 PMCID: PMC3052316 DOI: 10.1371/journal.pone.0017524] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 02/04/2011] [Indexed: 11/20/2022] Open
Abstract
Background The importance of genetic diversity in successful biological invasions is unclear. In animals, but not necessarily plants, increased genetic diversity is generally associated with successful colonization and establishment of novel habitats. The Oleander aphid, Aphis nerii, though native to the Mediterranean region, is an invasive pest species throughout much of the world. Feeding primarily on Oleander (Nerium oleander) and Milkweed (Asclepias spp.) under natural conditions, these plants are unlikely to support aphid populations year round in the southern US. The objective of this study was to describe the genetic variation within and among US populations of A. nerii, during extinction/recolonization events, to better understand the population ecology of this invasive species. Methodology/Principal Findings We used five microsatellite markers to assess genetic diversity over a two year period within and among three aphid populations separated by small (100 km) and large (3,700 km) geographic distances on two host plant species. Here we provide evidence for A. nerii “superclones”. Genotypic variation was absent in all populations (i.e., each population consisted of a single multilocus genotype (MLG) or “clone”) and the genetic composition of only one population completely changed across years. There was no evidence of sexual reproduction or host races on different plant species. Conclusions/Significance Aphis nerii is a well established invasive species despite having extremely low genetic diversity. As this aphid appears to be obligatorily asexual, it may share more similarities with clonally reproducing invasive plants, than with other animals. Patterns of temporal and geographic genetic variation, viewed in the context of its population dynamics, have important implications for the management of invasive pests and the evolutionary biology of asexual species.
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Affiliation(s)
- John Scott Harrison
- Department of Biology, Georgia Southern University, Statesboro, Georgia, United States of America.
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28
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Michel AP, Zhang W, Mian MAR. Genetic diversity and differentiation among laboratory and field populations of the soybean aphid, Aphis glycines. BULLETIN OF ENTOMOLOGICAL RESEARCH 2010; 100:727-734. [PMID: 20507673 DOI: 10.1017/s000748531000012x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The soybean aphid, Aphis glycines Matsumura, is a recent invasive pest of soybean in North America. Currently, much research is focused on developing and characterizing soybean cultivars expressing host-plant resistance. During the initial phases of host-plant resistance screening, many of these studies use soybean aphid laboratory populations. Previous studies in other systems have documented substantial differences among laboratory and field populations. Whether or not this pattern exists in A. glycines is unknown, but it is extremely important when estimating the level of selection and virulence to host-plant resistant soybeans. In this study, we used seven microsatellite markers to estimate and compare genetic diversity and differentiation among five laboratory and 12 field populations. Our results indicate that soybean aphid laboratory populations are severely lacking in genotypic diversity and show extreme genetic differentiation among each other and to field populations. Continued use of laboratory populations for initial soybean aphid resistance screening could lead to erroneous estimations of the potential success for host-plant resistance.
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Affiliation(s)
- A P Michel
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, OH 44691, USA.
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29
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POLIHRONAKIS MAXI, CATERINO MICHAELS, CHATZIMANOLIS STYLIANOS. Elucidating the phylogeographic structure among a mosaic of unisexual and bisexual populations of the weevil Geodercodes latipennis (Coleoptera: Curculionidae) in the Transverse Ranges of southern California. Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01542.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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YIN MINGBO, WOLINSKA JUSTYNA, GIEßLER SABINE. Clonal diversity, clonal persistence and rapid taxon replacement in natural populations of species and hybrids of the Daphnia longispina complex. Mol Ecol 2010; 19:4168-78. [DOI: 10.1111/j.1365-294x.2010.04807.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Simon JC, Stoeckel S, Tagu D. Evolutionary and functional insights into reproductive strategies of aphids. C R Biol 2010; 333:488-96. [DOI: 10.1016/j.crvi.2010.03.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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32
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Ross KG, Gotzek D, Ascunce MS, Shoemaker DD. Species delimitation: a case study in a problematic ant taxon. Syst Biol 2009; 59:162-84. [PMID: 20525628 DOI: 10.1093/sysbio/syp089] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Species delimitation has been invigorated as a discipline in systematics by an influx of new character sets, analytical methods, and conceptual advances. We use genetic data from 68 markers, combined with distributional, bioclimatic, and coloration information, to hypothesize boundaries of evolutionarily independent lineages (species) within the widespread and highly variable nominal fire ant species Solenopsis saevissima, a member of a species group containing invasive pests as well as species that are models for ecological and evolutionary research. Our integrated approach uses diverse methods of analysis to sequentially test whether populations meet specific operational criteria (contingent properties) for candidacy as morphologically cryptic species, including genetic clustering, monophyly, reproductive isolation, and occupation of distinctive niche space. We hypothesize that nominal S. saevissima comprises at least 4-6 previously unrecognized species, including several pairs whose parapatric distributions implicate the development of intrinsic premating or postmating barriers to gene flow. Our genetic data further suggest that regional genetic differentiation in S. saevissima has been influenced by hybridization with other nominal species occurring in sympatry or parapatry, including the quite distantly related Solenopsis geminata. The results of this study illustrate the importance of employing different classes of genetic data (coding and noncoding regions and nuclear and mitochondrial DNA [mtDNA] markers), different methods of genetic data analysis (tree-based and non-tree based methods), and different sources of data (genetic, morphological, and ecological data) to explicitly test various operational criteria for species boundaries in clades of recently diverged lineages, while warning against over reliance on any single data type (e.g., mtDNA sequence variation) when drawing inferences.
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Affiliation(s)
- Kenneth G Ross
- Department of Entomology, University of Georgia, Athens, GA 30602, USA.
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33
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Dombrovsky A, Arthaud L, Ledger TN, Tares S, Robichon A. Profiling the repertoire of phenotypes influenced by environmental cues that occur during asexual reproduction. Genome Res 2009; 19:2052-63. [PMID: 19635846 DOI: 10.1101/gr.091611.109] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The aphid Acyrthosiphon pisum population is composed of different morphs, such as winged and wingless parthenogens, males, and sexual females. The combined effect of reduced photoperiodicity and cold in fall triggers the apparition of sexual morphs. In contrast they reproduce asexually in spring and summer. In our current study, we provide evidence that clonal individuals display phenotypic variability within asexual morph categories. We describe that clones sharing the same morphological features, which arose from the same founder mother, constitute a repertoire of variants with distinct behavioral and physiological traits. Our results suggest that the prevailing environmental conditions influence the recruitment of adaptive phenotypes from a cohort of clonal individuals exhibiting considerable molecular diversity. However, we observed that the variability might be reduced or enhanced by external factors, but is never abolished in accordance with a model of stochastically produced phenotypes. This overall mechanism allows the renewal of colonies from a few adapted individuals that survive drastic episodic changes in a fluctuating environment.
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Affiliation(s)
- Aviv Dombrovsky
- INRA/CNRS/UNSA University Nice Sophia Antipolis, Sophia Antipolis 06903 BP 167, France.
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