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Baker CA, Guan XJ, Choi M, Murthy M. The role of fruitless in specifying courtship behaviors across divergent Drosophila species. SCIENCE ADVANCES 2024; 10:eadk1273. [PMID: 38478605 PMCID: PMC10936877 DOI: 10.1126/sciadv.adk1273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 02/08/2024] [Indexed: 04/20/2024]
Abstract
Sex-specific behaviors are critical for reproduction and species survival. The sex-specifically spliced transcription factor fruitless (fru) helps establish male courtship behaviors in invertebrates. Forcing male-specific fru (fruM) splicing in Drosophila melanogaster females produces male-typical behaviors while disrupting female-specific behaviors. However, whether fru's joint role in specifying male and inhibiting female behaviors is conserved across species is unknown. We used CRISPR-Cas9 to force FruM expression in female Drosophila virilis, a species in which males and females produce sex-specific songs. In contrast to D. melanogaster, in which one fruM allele is sufficient to generate male behaviors in females, two alleles are needed in D. virilis females. D. virilis females expressing FruM maintain the ability to sing female-typical song as well as lay eggs, whereas D. melanogaster FruM females cannot lay eggs. These results reveal potential differences in fru function between divergent species and underscore the importance of studying diverse behaviors and species for understanding the genetic basis of sex differences.
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Affiliation(s)
| | - Xiao-Juan Guan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
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2
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Deanhardt B, Duan Q, Du C, Soeder C, Morlote A, Garg D, Saha A, Jones CD, Volkan PC. Social experience and pheromone receptor activity reprogram gene expression in sensory neurons. G3 (BETHESDA, MD.) 2023; 13:jkad072. [PMID: 36972331 PMCID: PMC10234412 DOI: 10.1093/g3journal/jkad072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 03/11/2023] [Indexed: 06/29/2024]
Abstract
Social experience and pheromone signaling in olfactory neurons affect neuronal responses and male courtship behaviors in Drosophila. We previously showed that social experience and pheromone signaling modulate chromatin around behavioral switch gene fruitless, which encodes a transcription factor necessary and sufficient for male sexual behaviors. Fruitless drives social experience-dependent modulation of courtship behaviors and physiological sensory neuron responses to pheromone; however, the molecular mechanisms underlying this modulation of neural responses remain less clear. To identify the molecular mechanisms driving social experience-dependent changes in neuronal responses, we performed RNA-seq from antennal samples of mutants in pheromone receptors and fruitless, as well as grouped or isolated wild-type males. Genes affecting neuronal physiology and function, such as neurotransmitter receptors, ion channels, ion and membrane transporters, and odorant binding proteins are differentially regulated by social context and pheromone signaling. While we found that loss of pheromone detection only has small effects on differential promoter and exon usage within fruitless gene, many of the differentially regulated genes have Fruitless-binding sites or are bound by Fruitless in the nervous system. Recent studies showed that social experience and juvenile hormone signaling co-regulate fruitless chromatin to modify pheromone responses in olfactory neurons. Interestingly, genes involved in juvenile hormone metabolism are also misregulated in different social contexts and mutant backgrounds. Our results suggest that modulation of neuronal activity and behaviors in response to social experience and pheromone signaling likely arise due to large-scale changes in transcriptional programs for neuronal function downstream of behavioral switch gene function.
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Affiliation(s)
- Bryson Deanhardt
- Department of Biology, Duke University, Durham, NC 27708, USA
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Qichen Duan
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Chengcheng Du
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Charles Soeder
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Alec Morlote
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Deeya Garg
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Aishani Saha
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Corbin D Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Pelin Cayirlioglu Volkan
- Department of Biology, Duke University, Durham, NC 27708, USA
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
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Laslo M, Just J, Angelini DR. Theme and variation in the evolution of insect sex determination. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023; 340:162-181. [PMID: 35239250 PMCID: PMC10078687 DOI: 10.1002/jez.b.23125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 11/24/2021] [Accepted: 01/03/2022] [Indexed: 11/07/2022]
Abstract
The development of dimorphic adult sexes is a critical process for most animals, one that is subject to intense selection. Work in vertebrate and insect model species has revealed that sex determination mechanisms vary widely among animal groups. However, this variation is not uniform, with a limited number of conserved factors. Therefore, sex determination offers an excellent context to consider themes and variations in gene network evolution. Here we review the literature describing sex determination in diverse insects. We have screened public genomic sequence databases for orthologs and duplicates of 25 genes involved in insect sex determination, identifying patterns of presence and absence. These genes and a 3.5 reference set of 43 others were used to infer phylogenies and compared to accepted organismal relationships to examine patterns of congruence and divergence. The function of candidate genes for roles in sex determination (virilizer, female-lethal-2-d, transformer-2) and sex chromosome dosage compensation (male specific lethal-1, msl-2, msl-3) were tested using RNA interference in the milkweed bug, Oncopeltus fasciatus. None of these candidate genes exhibited conserved roles in these processes. Amidst this variation we wish to highlight the following themes for the evolution of sex determination: (1) Unique features within taxa influence network evolution. (2) Their position in the network influences a component's evolution. Our analyses also suggest an inverse association of protein sequence conservation with functional conservation.
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Affiliation(s)
- Mara Laslo
- Department of Cell Biology, Curriculum Fellows ProgramHarvard Medical School25 Shattuck StBostonMassachusettsUSA
| | - Josefine Just
- Department of Organismic and Evolutionary BiologyHarvard University26 Oxford StCambridgeMassachusettsUSA
- Department of BiologyColby College5734 Mayflower Hill DrWatervilleMaineUSA
| | - David R. Angelini
- Department of BiologyColby College5734 Mayflower Hill DrWatervilleMaineUSA
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Saccone G. A history of the genetic and molecular identification of genes and their functions controlling insect sex determination. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 151:103873. [PMID: 36400424 DOI: 10.1016/j.ibmb.2022.103873] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
The genetics of the sex determination regulatory cascade in Drosophila melanogaster has a fascinating history, interlinked with the foundation of the Genetics discipline itself. The discovery that alternative splicing rather than differential transcription is the molecular mechanism underlying the upstream control of sex differences in the Drosophila model system was surprising. This notion is now fully integrated into the scientific canon, appearing in many genetics textbooks and online education resources. In the last three decades, it was a key reference point for starting evolutionary studies in other insect species by using homology-based approaches. This review will introduce a very brief history of Drosophila genetics. It will describe the genetic and molecular approaches applied for the identifying and cloning key genes involved in sex determination in Drosophila and in many other insect species. These comparative analyses led to supporting the idea that sex-determining pathways have evolved mainly by recruiting different upstream signals/genes while maintaining widely conserved intermediate and downstream regulatory genes. The review also provides examples of the link between technological advances and research achievements, to stimulate reflections on how science is produced. It aims to hopefully strengthen the related historical and conceptual knowledge of general readers of other disciplines and of younger geneticists, often focused on the latest technical-molecular approaches.
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Affiliation(s)
- Giuseppe Saccone
- Department of Biology, University of Naples Federico II, Via Cinthia 26, 80126, Naples, Italy.
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Conditional knockdown of transformer in sheep blow fly suggests a role in repression of dosage compensation and potential for population suppression. PLoS Genet 2021; 17:e1009792. [PMID: 34662332 PMCID: PMC8553175 DOI: 10.1371/journal.pgen.1009792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/28/2021] [Accepted: 08/24/2021] [Indexed: 11/19/2022] Open
Abstract
The transformer (tra) gene is essential for female development in many insect species, including the Australian sheep blow fly, Lucilia cuprina. Sex-specific tra RNA splicing is controlled by Sex lethal (Sxl) in Drosophila melanogaster but is auto-regulated in L. cuprina. Sxl also represses X chromosome dosage compensation in female D. melanogaster. We have developed conditional Lctra RNAi knockdown strains using the tet-off system. Four strains did not produce females on diet without tetracycline and could potentially be used for genetic control of L. cuprina. In one strain, which showed both maternal and zygotic tTA expression, most XX transformed males died at the pupal stage. RNAseq and qRT-PCR analyses of mid-stage pupae showed increased expression of X-linked genes in XX individuals. These results suggest that Lctra promotes somatic sexual differentiation and inhibits X chromosome dosage compensation in female L. cuprina. However, XX flies homozygous for a loss-of-function Lctra knockin mutation were fully transformed and showed high pupal eclosion. Two of five X-linked genes examined showed a significant increase in mRNA levels in XX males. The stronger phenotype in the RNAi knockdown strain could indicate that maternal Lctra expression may be essential for initiation of dosage compensation suppression in female embryos.
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Mine S, Sumitani M, Aoki F, Hatakeyama M, Suzuki MG. Effects of Functional Depletion of Doublesex on Male Development in the Sawfly, Athalia rosae. INSECTS 2021; 12:insects12100849. [PMID: 34680618 PMCID: PMC8538284 DOI: 10.3390/insects12100849] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 01/04/2023]
Abstract
Simple Summary The sawfly, Athalia rosae, exploits a haplodiploid mode of reproduction, in which fertilized eggs develop into diploid females, whereas unfertilized eggs parthenogenetically develop into haploid males. The doublesex (dsx) gene is a well-conserved transcription factor that regulates sexual differentiation in insects. In the present study, we knocked down the A. rosae ortholog of dsx (Ardsx) during several developmental stages with repeated double-stranded RNA (dsRNA) injections. As a result, knockdown of Ardsx in haploid males caused almost complete male-to-female sex reversal, but the resulting eggs were infertile. The same knockdown approach using diploid males caused complete male-to-female sex reversal; they were able to produce fertile eggs and exhibited female behaviors. The same RNAi treatment did not affect female differentiation. These results demonstrated that dsx in the sawfly is essential for male development and its depletion caused complete male-to-female sex reversal. This is the first demonstration of functional depletion of dsx not causing intersexuality but inducing total sex reversal in males instead. Abstract The doublesex (dsx) gene, which encodes a transcription factor, regulates sexual differentiation in insects. Sex-specific splicing of dsx occurs to yield male- and female-specific isoforms, which promote male and female development, respectively. Thus, functional disruption of dsx leads to an intersexual phenotype in both sexes. We previously identified a dsx ortholog in the sawfly, Athalia rosae. Similar to dsx in other insects, dsx in the sawfly yields different isoforms in males and females as a result of alternative splicing. The sawfly exploits a haplodiploid mode of reproduction, in which fertilized eggs develop into diploid females, whereas unfertilized eggs parthenogenetically develop into haploid males. In the present study, we knocked down the A. rosae ortholog of dsx (Ardsx) during several developmental stages with repeated double-stranded RNA (dsRNA) injections. Knockdown of Ardsx via parental RNA interference (RNAi), which enables knockdown of genes in offspring embryos, led to a lack of internal and external genitalia in haploid male progeny. Additional injection of dsRNA targeting Ardsx in these animals caused almost complete male-to-female sex reversal, but the resulting eggs were infertile. Notably, the same knockdown approach using diploid males obtained by sib-crossing caused complete male-to-female sex reversal; they were morphologically and behaviorally females. The same RNAi treatment did not affect female differentiation. These results indicate that dsx in the sawfly is essential for male development and its depletion caused complete male-to-female sex reversal. This is the first demonstration of functional depletion of dsx not causing intersexuality but inducing total sex reversal in males instead.
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Affiliation(s)
- Shotaro Mine
- Department of Biosciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan;
| | - Megumi Sumitani
- Division of Biotechnology, Institute of Agrobiological Sciences, NARO, Owashi, Tsukuba 305-8634, Japan;
| | - Fugaku Aoki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562, Japan;
| | - Masatsugu Hatakeyama
- Division of Applied Genetics, Institute of Agrobiological Sciences, NARO, Owashi, Tsukuba 305-8634, Japan;
| | - Masataka G. Suzuki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562, Japan;
- Correspondence: ; Tel.: +81-4-7136-3694
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Adhikari K, Son JH, Rensink AH, Jaweria J, Bopp D, Beukeboom LW, Meisel RP. Temperature-dependent effects of house fly proto-Y chromosomes on gene expression could be responsible for fitness differences that maintain polygenic sex determination. Mol Ecol 2021; 30:5704-5720. [PMID: 34449942 DOI: 10.1111/mec.16148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 08/20/2021] [Indexed: 12/21/2022]
Abstract
Sex determination, the developmental process by which sexually dimorphic phenotypes are established, evolves fast. Evolutionary turnover in a sex determination pathway may occur via selection on alleles that are genetically linked to a new master sex determining locus on a newly formed proto-sex chromosome. Species with polygenic sex determination, in which master regulatory genes are found on multiple different proto-sex chromosomes, are informative models to study the evolution of sex determination and sex chromosomes. House flies are such a model system, with male determining loci possible on all six chromosomes and a female-determiner on one of the chromosomes as well. The two most common male-determining proto-Y chromosomes form latitudinal clines on multiple continents, suggesting that temperature variation is an important selection pressure responsible for maintaining polygenic sex determination in this species. Temperature-dependent fitness effects could be manifested through temperature-dependent gene expression differences across proto-Y chromosome genotypes. These gene expression differences may be the result of cis regulatory variants that affect the expression of genes on the proto-sex chromosomes, or trans effects of the proto-Y chromosomes on genes elswhere in the genome. We used RNA-seq to identify genes whose expression depends on proto-Y chromosome genotype and temperature in adult male house flies. We found no evidence for ecologically meaningful temperature-dependent expression differences of sex determining genes between male genotypes, but we were probably not sampling an appropriate developmental time-point to identify such effects. In contrast, we identified many other genes whose expression depends on the interaction between proto-Y chromosome genotype and temperature, including genes that encode proteins involved in reproduction, metabolism, lifespan, stress response, and immunity. Notably, genes with genotype-by-temperature interactions on expression were not enriched on the proto-sex chromosomes. Moreover, there was no evidence that temperature-dependent expression is driven by chromosome-wide cis-regulatory divergence between the proto-Y and proto-X alleles. Therefore, if temperature-dependent gene expression is responsible for differences in phenotypes and fitness of proto-Y genotypes across house fly populations, these effects are driven by a small number of temperature-dependent alleles on the proto-Y chromosomes that may have trans effects on the expression of genes on other chromosomes.
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Affiliation(s)
- Kiran Adhikari
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Jae Hak Son
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Anna H Rensink
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Jaweria Jaweria
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Daniel Bopp
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Leo W Beukeboom
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
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Zhou Y, Yang P, Xie S, Shi M, Huang J, Wang Z, Chen X. Comparative Transcriptome Analysis Reveals Sex-Based Differences during the Development of the Adult Parasitic Wasp Cotesia vestalis (Hymenoptera: Braconidae). Genes (Basel) 2021; 12:genes12060896. [PMID: 34200644 PMCID: PMC8228208 DOI: 10.3390/genes12060896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/05/2021] [Accepted: 06/07/2021] [Indexed: 12/19/2022] Open
Abstract
The endoparasitic wasp Cotesia vestalis is an important biological agent for controlling the population of Plutella xylostella, a major pest of cruciferous crops worldwide. Though the genome of C. vestalis has recently been reported, molecular mechanisms associated with sexual development have not been comprehensively studied. Here, we combined PacBio Iso-Seq and Illumina RNA-Seq to perform genome-wide profiling of pharate adult and adult development of male and female C. vestalis. Taking advantage of Iso-Seq full-length reads, we identified 14,466 novel transcripts as well as 8770 lncRNAs, with many lncRNAs showing a sex- and stage-specific expression pattern. The differentially expressed gene (DEG) analyses showed 2125 stage-specific and 326 sex-specific expressed genes. We also found that 4819 genes showed 11,856 alternative splicing events through combining the Iso-Seq and RNA-Seq data. The results of comparative analyses showed that most genes were alternatively spliced across developmental stages, and alternative splicing (AS) events were more prevalent in females than in males. Furthermore, we identified six sex-determining genes in this parasitic wasp and verified their sex-specific alternative splicing profiles. Specifically, the characterization of feminizer and doublesex splicing between male and female implies a conserved regulation mechanism of sexual development in parasitic wasps.
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Affiliation(s)
- Yuenan Zhou
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
| | - Pei Yang
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
| | - Shuang Xie
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
| | - Min Shi
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
| | - Jianhua Huang
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China
- Zhejiang Provincial Key Lab of Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
| | - Zhizhi Wang
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China
- Correspondence: (Z.W.); (X.C.)
| | - Xuexin Chen
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (P.Y.); (S.X.); (M.S.); (J.H.)
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China
- Zhejiang Provincial Key Lab of Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
- State Key Lab of Rice Biology, Zhejiang University, Hangzhou 310058, China
- Correspondence: (Z.W.); (X.C.)
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Meisel RP. The maintenance of polygenic sex determination depends on the dominance of fitness effects which are predictive of the role of sexual antagonism. G3 (BETHESDA, MD.) 2021; 11:6261074. [PMID: 33930135 PMCID: PMC8496315 DOI: 10.1093/g3journal/jkab149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/23/2021] [Indexed: 12/18/2022]
Abstract
In species with polygenic sex determination (PSD), multiple male- and female-determining loci on different proto-sex chromosomes segregate as polymorphisms within populations. The extent to which these polymorphisms are at stable equilibria is not yet resolved. Previous work demonstrated that PSD is most likely to be maintained as a stable polymorphism when the proto-sex chromosomes have opposite (sexually antagonistic) fitness effects in males and females. However, these models usually consider PSD systems with only two proto-sex chromosomes, or they do not broadly consider the dominance of the alleles under selection. To address these shortcomings, I used forward population genetic simulations to identify selection pressures that can maintain PSD under different dominance scenarios in a system with more than two proto-sex chromosomes (modeled after the house fly). I found that overdominant fitness effects of male-determining proto-Y chromosomes are more likely to maintain PSD than dominant, recessive, or additive fitness effects. The overdominant fitness effects that maintain PSD tend to have proto-Y chromosomes with sexually antagonistic effects (male-beneficial and female-detrimental). In contrast, dominant fitness effects that maintain PSD tend to have sexually antagonistic multi-chromosomal genotypes, but the individual proto-sex chromosomes do not have sexually antagonistic effects. These results demonstrate that sexual antagonism can be an emergent property of the multi-chromosome genotype without individual sexually antagonistic chromosomes. My results further illustrate how the dominance of fitness effects has consequences for both the likelihood that PSD will be maintained as well as the role sexually antagonistic selection is expected to play in maintaining the polymorphism.
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Affiliation(s)
- Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
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10
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The transformer-2 and fruitless characterisation with developmental expression profiles of sex-determining genes in Bactrocera dorsalis and B. correcta. Sci Rep 2020; 10:17938. [PMID: 33087807 PMCID: PMC7578103 DOI: 10.1038/s41598-020-74856-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
Sex determination in tephritid fruit flies involves a signaling cascade of alternatively spliced genes. The Transformer (TRA) and Transformer-2 (TRA-2) complex establishes an autoregulatory loop switching sex-specific splicing of tra pre-mRNA in females. The TRA/TRA-2 complex also regulates the sex-specific splicing of downstream effector genes, doublesex (dsx) and fruitless (fru). In Ceratitis capitata, a Maleness-on the-Y (MoY) gene modulates sex-specifically spliced Cctra pre-mRNA and results in the breakdown of the Cctra autoregulatory loop in males. In this study, the tra-2 and fru genes were characterised in two key pests, Bactrocera dorsalis and B. correcta. The tra-2 genes showed high degrees of conservation among tephritids. The complex gene organisation for each of Bdfru and Bcfru were identified. There are sex-specific and non sex-specific transcripts generated by alternative promoters as found in Drosophila melanogaster and other insects. RNAi knockdown of Bdtra transcripts showed that BdTRA controls the sex-specific splicing of Bddsx and Bdfru pre-mRNAs. Developmental expression analysis shows that multiple splice variants of Bdtra and Bctra RNAs are present before and during cellular blastoderm formation and that the mature sex-specific variants become fixed later in embryogenesis. Furthermore, the BddsxM splice variants are found in early embryos at the beginning of gastulation, but BdfruM does not appear until the larval stage. We proposed that the zygotic tra loop is initiated in both female and male embryos before becoming automatised or abolished by MoY, respectively.
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Scott MJ, Benoit JB, Davis RJ, Bailey ST, Varga V, Martinson EO, Hickner PV, Syed Z, Cardoso GA, Torres TT, Weirauch MT, Scholl EH, Phillippy AM, Sagel A, Vasquez M, Quintero G, Skoda SR. Genomic analyses of a livestock pest, the New World screwworm, find potential targets for genetic control programs. Commun Biol 2020; 3:424. [PMID: 32753684 PMCID: PMC7403345 DOI: 10.1038/s42003-020-01152-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 07/14/2020] [Indexed: 12/13/2022] Open
Abstract
The New World Screwworm fly, Cochliomyia hominivorax, is a major pest of livestock in South America and Caribbean. However, few genomic resources have been available for this species. A genome of 534 Mb was assembled from long read PacBio DNA sequencing of DNA from a highly inbred strain. Analysis of molecular evolution identified 40 genes that are likely under positive selection. Developmental RNA-seq analysis identified specific genes associated with each stage. We identify and analyze the expression of genes that are likely important for host-seeking behavior (chemosensory), development of larvae in open wounds in warm-blooded animals (heat shock protein, immune response) and for building transgenic strains for genetic control programs including gene drive (sex determination, germline). This study will underpin future experiments aimed at understanding the parasitic lifestyle of the screwworm fly and greatly facilitate future development of strains for efficient systems for genetic control of screwworm.
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Affiliation(s)
- Maxwell J Scott
- Department of Entomology and Plant Pathology, North Carolina State University, Campus Box 7613, Raleigh, NC, 27695-7613, USA.
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, McMicken School of Arts and Sciences, Cincinnati, OH, 45221, USA
| | - Rebecca J Davis
- Department of Entomology and Plant Pathology, North Carolina State University, Campus Box 7613, Raleigh, NC, 27695-7613, USA
| | - Samuel T Bailey
- Department of Biological Sciences, University of Cincinnati, McMicken School of Arts and Sciences, Cincinnati, OH, 45221, USA
| | - Virag Varga
- Department of Biological Sciences, University of Cincinnati, McMicken School of Arts and Sciences, Cincinnati, OH, 45221, USA
| | - Ellen O Martinson
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Paul V Hickner
- Department of Entomology, University of Kentucky, Lexington, KY, 40546, USA
| | | | - Gisele A Cardoso
- Department of Genetics and Evolutionary Biology, University of São Paulo, São Paulo, Brazil
| | - Tatiana T Torres
- Department of Genetics and Evolutionary Biology, University of São Paulo, São Paulo, Brazil
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Divisions of Biomedical Informatics and Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Elizabeth H Scholl
- Bioinformatics Research Center, North Carolina State University, Campus Box 7566, Raleigh, NC, 27695-7566, USA
| | - Adam M Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD, 20892, USA
| | | | | | | | - Steven R Skoda
- USDA-ARS, Tick and Biting Fly Research Unit, Knipling-Bushland Livestock Insects Research Laboratory, 2700 Fredericksburg Rd., Kerrville, TX, 78028, USA
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Xu J, Liu W, Yang D, Chen S, Chen K, Liu Z, Yang X, Meng J, Zhu G, Dong S, Zhang Y, Zhan S, Wang G, Huang Y. Regulation of olfactory-based sex behaviors in the silkworm by genes in the sex-determination cascade. PLoS Genet 2020; 16:e1008622. [PMID: 32520935 PMCID: PMC7307793 DOI: 10.1371/journal.pgen.1008622] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/22/2020] [Accepted: 05/04/2020] [Indexed: 11/28/2022] Open
Abstract
Insect courtship and mating depend on integration of olfactory, visual, and tactile cues. Compared to other insects, Bombyx mori, the domesticated silkworm, has relatively simple sexual behaviors as it cannot fly. Here by using CRISPR/Cas9 and electrophysiological techniques we found that courtship and mating behaviors are regulated in male silk moths by mutating genes in the sex determination cascade belonging to two conserved pathways. Loss of Bmdsx gene expression significantly reduced the peripheral perception of the major pheromone component bombykol by reducing expression of the product of the BmOR1 gene which completely blocked courtship in adult males. Interestingly, we found that mating behavior was regulated independently by another sexual differentiation gene, Bmfru. Loss of Bmfru completely blocked mating, but males displayed normal courtship behavior. Lack of Bmfru expression significantly reduced the perception of the minor pheromone component bombykal due to the down regulation of BmOR3 expression; further, functional analysis revealed that loss of the product of BmOR3 played a key role in terminating male mating behavior. Our results suggest that Bmdsx and Bmfru are at the base of the two primary pathways that regulate olfactory-based sexual behavior. The fundamental insect sexual behaviors, courtship and mating, result from successful integration of olfactory, vision, tactile and other complex innate behaviors. In the widely used insect model, Drosophila melanogaster, the sex determination cascade genes fruitless and doublesex are involved in the regulation of courtship and mating behaviors; however, little is known about the function of these sexual differentiation genes in regulating sex behaviors of Lepidoptera. Here we combine genetics and electrophysiology to investigate regulation pathway of sexual behaviors in the model lepidopteran insect, the domesticated silk moth, Bombyx mori. Our results support the presence of two genetic pathways in B. mori, named Bmdsx-BmOR1-bombykol and Bmfru-BmOR3-bombykal, which control distinct aspects of male sexual behavior that are modulated by olfaction. This is the first comprehensive report about the role of sex differentiation genes in the male sexual behavior in the silk moth.
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Affiliation(s)
- Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Wei Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dehong Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Shuqing Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Kai Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Zulian Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xu Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jing Meng
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Guanheng Zhu
- Education Ministry Key Laboratory of Integrated Management of Crop Disease and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Shuanglin Dong
- Education Ministry Key Laboratory of Integrated Management of Crop Disease and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yong Zhang
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
| | - Shuai Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail: (GW); (YH)
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (GW); (YH)
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McKelvey EG, Fabre CC. Recent neurogenetic findings in insect courtship behaviour. CURRENT OPINION IN INSECT SCIENCE 2019; 36:103-110. [PMID: 31546094 DOI: 10.1016/j.cois.2019.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/30/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
Insect courtship parades consist of series of innate and stereotyped behaviours that become hardwired-in during the development of the nervous system. As such, insect courtship behaviour provides an excellent model for probing the principles of neuronal assembly, which underlie patterns of behaviour. Here, we present the main advances of recent studies - in species all the way from flies to planthoppers - and we envisage how these could lead to further propitious findings.
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Affiliation(s)
- Eleanor Gz McKelvey
- University of Cambridge, Department of Zoology, Downing Street, Cambridge CB2 3EJ, United Kingdom
| | - Caroline Cg Fabre
- University of Cambridge, Department of Zoology, Downing Street, Cambridge CB2 3EJ, United Kingdom.
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Watanabe T. Evolution of the neural sex-determination system in insects: does fruitless homologue regulate neural sexual dimorphism in basal insects? INSECT MOLECULAR BIOLOGY 2019; 28:807-827. [PMID: 31066110 DOI: 10.1111/imb.12590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the brain of holometabolous insects such as the fruit fly Drosophila melanogaster, the fruitless gene produces sex-specific gene products under the control of the sex-specific splicing cascade and contributes to the formation of the sexually dimorphic circuits. Similar sex-specific gene products of fruitless homologues have been identified in other holometabolous insects such as mosquitoes and a parasitic wasp, suggesting the fruitless-dependent neural sex-determination system is widely conserved amongst holometabolous insects. However, it remains obscure whether the fruitless-dependent neural sex-determination system is present in basal hemimetabolous insects. To address this issue, identification, characterization, and expression analyses of the fruitless homologue were conducted in the two-spotted cricket, Gryllus bimaculatus, as a model hemimetabolous insect. The Gryllus fruitless gene encodes multiple isoforms with a unique zinc finger domain, and does not encode a sex-specific gene product. The Gryllus Fruitless protein is broadly expressed in the neurones and glial cells in the brain, and there was no prominent sex-related difference in the expression levels of Gryllus fruitless isoforms. The results suggest that the Gryllus fruitless gene is not involved in the neural sex-determination in the cricket brain.
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Affiliation(s)
- T Watanabe
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
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15
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Wexler J, Delaney EK, Belles X, Schal C, Wada-Katsumata A, Amicucci MJ, Kopp A. Hemimetabolous insects elucidate the origin of sexual development via alternative splicing. eLife 2019; 8:e47490. [PMID: 31478483 PMCID: PMC6721801 DOI: 10.7554/elife.47490] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 08/11/2019] [Indexed: 02/02/2023] Open
Abstract
Insects are the only known animals in which sexual differentiation is controlled by sex-specific splicing. The doublesex transcription factor produces distinct male and female isoforms, which are both essential for sex-specific development. dsx splicing depends on transformer, which is also alternatively spliced such that functional Tra is only present in females. This pathway has evolved from an ancestral mechanism where dsx was independent of tra and expressed and required only in males. To reconstruct this transition, we examined three basal, hemimetabolous insect orders: Hemiptera, Phthiraptera, and Blattodea. We show that tra and dsx have distinct functions in these insects, reflecting different stages in the changeover from a transcription-based to a splicing-based mode of sexual differentiation. We propose that the canonical insect tra-dsx pathway evolved via merger between expanding dsx function (from males to both sexes) and narrowing tra function (from a general splicing factor to dedicated regulator of dsx).
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Affiliation(s)
- Judith Wexler
- Department of Evolution and EcologyUniversity of California, DavisDavisUnited States
| | - Emily Kay Delaney
- Department of Evolution and EcologyUniversity of California, DavisDavisUnited States
| | - Xavier Belles
- Institut de Biologia EvolutivaConsejo Superior de Investigaciones Cientificas, Universitat Pompeu FabraBarcelonaSpain
| | - Coby Schal
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighUnited States
| | - Ayako Wada-Katsumata
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighUnited States
| | - Matthew J Amicucci
- Department of ChemistryUniversity of California, DavisDavisUnited States
| | - Artyom Kopp
- Department of Evolution and EcologyUniversity of California, DavisDavisUnited States
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16
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Son JH, Kohlbrenner T, Heinze S, Beukeboom LW, Bopp D, Meisel RP. Minimal Effects of Proto- Y Chromosomes on House Fly Gene Expression in Spite of Evidence that Selection Maintains Stable Polygenic Sex Determination. Genetics 2019; 213:313-327. [PMID: 31315889 PMCID: PMC6727804 DOI: 10.1534/genetics.119.302441] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 07/10/2019] [Indexed: 02/05/2023] Open
Abstract
Sex determination, the developmental process by which organismal sex is established, evolves fast, often due to changes in the master regulators at the top of the pathway. Additionally, in species with polygenic sex determination, multiple different master regulators segregate as polymorphisms. Understanding the forces that maintain polygenic sex determination can be informative of the factors that drive the evolution of sex determination. The house fly, Musca domestica, is a well-suited model to those ends because natural populations harbor male-determining loci on each of the six chromosomes and a biallelic female determiner. To investigate how natural selection maintains polygenic sex determination in the house fly, we assayed the phenotypic effects of proto-Y chromosomes by performing mRNA-sequencing experiments to measure gene expression in house fly males carrying different proto-Y chromosomes. We find that the proto-Y chromosomes have similar effects as a nonsex-determining autosome. In addition, we created sex-reversed males without any proto-Y chromosomes and they had nearly identical gene expression profiles as genotypic males. Therefore, the proto-Y chromosomes have a minor effect on male gene expression, consistent with previously described minimal X-Y sequence differences. Despite these minimal differences, we find evidence for a disproportionate effect of one proto-Y chromosome on male-biased expression, which could be partially responsible for fitness differences between males with different proto-Y chromosome genotypes. Therefore our results suggest that, if natural selection maintains polygenic sex determination in house fly via gene expression differences, the phenotypes under selection likely depend on a small number of genetic targets.
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Affiliation(s)
- Jae Hak Son
- Department of Biology and Biochemistry, University of Houston, Texas 77204-5001
| | - Tea Kohlbrenner
- Institute of Molecular Life Sciences, University of Zurich, Switzerland CH-8057
| | - Svenia Heinze
- Institute of Molecular Life Sciences, University of Zurich, Switzerland CH-8057
| | - Leo W Beukeboom
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands 9700
| | - Daniel Bopp
- Institute of Molecular Life Sciences, University of Zurich, Switzerland CH-8057
| | - Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Texas 77204-5001
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17
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Schenkel MA, Pen I, Beukeboom LW, Billeter J. Making sense of intralocus and interlocus sexual conflict. Ecol Evol 2018; 8:13035-13050. [PMID: 30619603 PMCID: PMC6309128 DOI: 10.1002/ece3.4629] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 01/13/2023] Open
Abstract
Sexual conflict occurs because males and females are exposed to different selection pressures. This can affect many aspects of female and male biology, such as physiology, behavior, genetics, and even population ecology. Its broad impact has caused widespread interest in sexual conflict. However, a key aspect of sexual conflict is often confused; it comprises two distinct forms: intralocus and interlocus sexual conflict (IASC and IRSC). Although both are caused by sex differences in selection, they operate via different proximate and ultimate mechanisms. Intralocus sexual conflict and IRSC are often not clearly defined as separate processes in the scientific literature, which impedes a proper understanding of each form as well as of their relative impact on sexual conflict. Furthermore, our current knowledge of the genetics of these phenomena is severely limited. This prevents us from empirically testing numerous theories regarding the role of these two forms of sexual conflict in evolution. Here, we clarify the distinction between IASC and IRSC, by discussing how male and female interests differ, how and when sex-specific adaptation occurs, and how this may lead to evolutionary change. We then describe a framework for their study, focusing on how future experiments may help identify the genetics underlying these phenomena. Through this, we hope to promote a more critical reflection on IASC and IRSC as well as underline the necessity of genetic and mechanistic studies of these two phenomena.
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Affiliation(s)
- Martijn A. Schenkel
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Ido Pen
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Leo W. Beukeboom
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Jean‐Christophe Billeter
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
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18
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Li P, Liu Y, Luo D, Song C, Cui Z. Two spliced isoforms of the sex-determination gene fruitless in the Chinese mitten crab Eriocheir sinensis. Comp Biochem Physiol B Biochem Mol Biol 2017; 208-209:75-83. [PMID: 28438684 DOI: 10.1016/j.cbpb.2017.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 04/11/2017] [Accepted: 04/17/2017] [Indexed: 01/06/2023]
Abstract
The fruitless (fru) gene plays an important role in the sex determination pathway and courtship behavior of Drosophila melanogaster. In the present study, two fru isoforms (Esfru1 and Esfru2) were identified from the Chinese mitten crab Eriocheir sinensis. Sequence analysis showed that Esfru1 and Esfru2 were encoded by the same genomic locus and generated by alternative splicing of pre-mRNA. Esfru1 had all introns completely spliced out, while Esfru2 had a longer exon1 with an additional 78bp sequence. They both contained a conserved BTB domain which was also found in D. melanogaster Fru isoforms. Analysis on temporal expression profiles of Esfru1-2 (a common region of Esfru1 and Esfru2) and Esfru2 (a specific region of Esfru2) showed that they expressed in similar patterns during embryonic development but in different patterns during larval development. The expression of Esfru1-2 decreased gradually from zoea III stage, however, Esfru2 increased from zoea IV stage and reached the peak at megalopa stage. Expression distribution in tissues and in situ hybridization analysis revealed that they showed sexually dimorphic expression in gonads, hepatopancreas and brains. Esfru1-2 showed significantly higher expression in female gonads and hepatopancreas than in males, but highly expressed in male brains than that in females. Interestingly, Esfru2 was displayed in a male-specific manner in each tissue, especially in gonads and hepatopancreas. Our results indicate that Esfru1 might be involved in both sexual brain neuronal structure development and related to female-specific character development. Esfru2 may participate in male-specific character development. This is the first report that characterizes two spliced variants of fru in crustaceans and provides basic information for further functional studies of the crab sex-determination mechanism.
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Affiliation(s)
- Peiyao Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Danli Luo
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Chengwen Song
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhaoxia Cui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
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19
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Hamm RL, Meisel RP, Scott JG. The evolving puzzle of autosomal versus Y-linked male determination in Musca domestica. G3 (BETHESDA, MD.) 2014; 5:371-84. [PMID: 25552607 PMCID: PMC4349091 DOI: 10.1534/g3.114.014795] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 12/27/2014] [Indexed: 11/18/2022]
Abstract
Sex determination is one of the most rapidly evolving developmental pathways, but the factors responsible for this fast evolution are not well resolved. The house fly, Musca domestica, is an ideal model for studying sex determination because house fly sex determination is polygenic and varies considerably between populations. Male house flies possess a male-determining locus, the M factor, which can be located on the Y or X chromosome or any of the five autosomes. There can be a single M or multiple M factors present in an individual male, in heterozygous or homozygous condition. Males with multiple copies of M skew the sex ratio toward the production of males. Potentially in response to these male-biased sex ratios, an allele of the gene transformer, Md-tra(D), promotes female development in the presence of one or multiple M factors. There have been many studies to determine the linkage and frequency of these male determining factors and the frequency of Md-tra(D) chromosomes in populations from around the world. This review provides a summary of the information available to date regarding the patterns of distribution of autosomal, X-linked and Y-linked M factors, the relative frequencies of the linkage of M, the changes in frequencies found in field populations, and the fitness of males with autosomal M factors vs. Y-linked M. We evaluate this natural variation in the house fly sex determination pathway in light of models of the evolution of sex determination.
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Affiliation(s)
| | - Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204
| | - Jeffrey G Scott
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York 14853
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20
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Vigoder FDM, Ritchie MG, Gibson G, Peixoto AA. Acoustic communication in insect disease vectors. Mem Inst Oswaldo Cruz 2014; 108 Suppl 1:26-33. [PMID: 24473800 PMCID: PMC4109177 DOI: 10.1590/0074-0276130390] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/30/2013] [Indexed: 11/21/2022] Open
Abstract
Acoustic signalling has been extensively studied in insect species, which has led to a better understanding of sexual communication, sexual selection and modes of speciation. The significance of acoustic signals for a blood-sucking insect was first reported in the XIX century by Christopher Johnston, studying the hearing organs of mosquitoes, but has received relatively little attention in other disease vectors until recently. Acoustic signals are often associated with mating behaviour and sexual selection and changes in signalling can lead to rapid evolutionary divergence and may ultimately contribute to the process of speciation. Songs can also have implications for the success of novel methods of disease control such as determining the mating competitiveness of modified insects used for mass-release control programs. Species-specific sound "signatures" may help identify incipient species within species complexes that may be of epidemiological significance, e.g. of higher vectorial capacity, thereby enabling the application of more focussed control measures to optimise the reduction of pathogen transmission. Although the study of acoustic communication in insect vectors has been relatively limited, this review of research demonstrates their value as models for understanding both the functional and evolutionary significance of acoustic communication in insects.
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Affiliation(s)
- Felipe de Mello Vigoder
- Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz-Fiocruz, Brasil, Rio de JaneiroRJ, Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
| | - Michael Gordon Ritchie
- Centre for Biological Diversity, School of Biology, University of St Andrews, Scotland, Fife, Centre for Biological Diversity, School of Biology, University of St Andrews, Fife, Scotland, UK
| | - Gabriella Gibson
- Natural Resources Institute, University of Greenwich,, UK, Chatham MaritimeKent, Natural Resources Institute, University of Greenwich, Medway Campus, Chatham Maritime, Kent, UK
| | - Alexandre Afranio Peixoto
- Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz-Fiocruz, Brasil, Rio de JaneiroRJ, Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
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Male-specific phosphorylated SR proteins in adult flies of the Mediterranean fruitfly Ceratitis capitata. BMC Genet 2014; 15 Suppl 2:S6. [PMID: 25472723 PMCID: PMC4255826 DOI: 10.1186/1471-2156-15-s2-s6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alternative splicing is a widely used mechanism of gene regulation in sex determination pathways of Insects. In species from orders as distant as Diptera, Hymenoptera and Coleoptera, female differentiation relies on the activities of conserved splicing regulators, TRA and TRA-2, promoting female-specific expression of the global effector doublesex (dsx). Less understood is to what extent post-translational modifications of splicing regulators plays a role in this pathway. In Drosophila melanogaster phosphorylation of TRA, TRA-2 and the general RBP1 factor by the LAMMER kinase doa (darkener of apricot) is required for proper female sex determination. To explore whether this is a general feature of the pathway we examined sex-specific differences in phosphorylation levels of SR splicing factors in the dipteran species D. melanogaster, Ceratitis capitata (Medfly) and Musca domestica (Housefly). We found a distinct and reproducible pattern of male-specific phosphorylation on protein extracts enriched for SR proteins in C. capitata suggesting that differential phosphorylation may also contribute to the regulation of sex-specific splicing in the Medfly.
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Bopp D, Saccone G, Beye M. Sex determination in insects: variations on a common theme. Sex Dev 2013; 8:20-8. [PMID: 24335049 DOI: 10.1159/000356458] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Recent studies in a representative selection of holometabolous insects suggest that, despite diversity at the instructive level, the signal-relaying part of the sex-determining pathway is remarkably well conserved. In principle, it is composed of the transformer gene (tra), which acts as a common binary switch that transduces the selected sexual fate, female when ON, male when OFF, to the downstream effector doublesex(dsx) that controls overt sexual differentiation. An interesting recurrent feature is that tra is switched ON in the early zygote by maternally provisioned tra activity. Different male-determining signals evolved, which prevent maternal activation of zygotic tra to allow for male development. In some species, where lack of maternal activation leaves tra in the OFF state, novel female-determining signals were deployed to activate zygotic tra. It appears that both the instructive end of the pathway upstream of tra as well as the executive end downstream of dsx are primary targets of evolutionary divergence, while the transduction part seems less prone to changes. We propose that this is a feature shared with many other signaling cascades that regulate developmental fates.
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Affiliation(s)
- D Bopp
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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