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Gouda MNR, D S, Gaikwad K, Prabha R, Kumar A, Subramanian S. Elucidation of ejaculatory bulb proteins in Bemisia tabaci Asia-1 and Asia II-1 and confirmation of their mating transfer via RNAi. Mol Biol Rep 2024; 51:861. [PMID: 39068620 DOI: 10.1007/s11033-024-09816-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 07/22/2024] [Indexed: 07/30/2024]
Abstract
BACKGROUND Bemisia tabaci, a significant agricultural pest in Asia, contains distinct genetic groups, Asia-1 and Asia II-1. Understanding its reproductive biology, particularly the role of ejaculatory bulb proteins (EBPs) in mating, is crucial. However, EBPs in B. tabaci were not well characterised until this study. METHODS AND RESULTS The EBPs have been characterised in the Asia-1 and Asia II-1 genetic groups of the whitefly B. tabaci, prevalent in Asia. The transcriptomic analysis yielded over 40,000,000 and 30,000,000 annotated transcripts, respectively, from Asia II-1 and Asia-1. Differential gene expression revealed the presence of 270 upregulated and 198 downregulated genes, with significant differences between these two genetic groups. Orphan genes (1992 numbers) were identified in both genetic groups. We report, for the first time, full-length sequences of EBP genes from B. tabaci. The 10 EBPs each deduced in B. tabaci Asia-1 and Asia II-1 are structurally akin to chemosensory proteins having four conserved cysteine residues. Additionally, we did domain analysis, protein structure prediction, mapping of these EBPs in the chromosomes of B. tabaci, and phylogenetic analysis to track their evolutionary lineage. We have specifically demonstrated the transfer of EBPs from males to females during mating using qPCR and further validated the transfer of EBPs through RNAi. Specifically, we targeted the highly expressed EBPs (EBP-3, 7, and 8 in BtAsia1; EBP-8, 9, and 10 in BtAsia II-1) through feeding bioassays of dsRNAs. Tracking by qPCR revealed that the females, when mated with dsRNA-treated males, did not show expression of the specific EBP, suggesting that the silencing of these genes in males hinders the transfer of EBP to females during mating. CONCLUSION Our findings provide novel insights into the genomic contours of EBPs in B. tabaci and underscore the potential of RNAi-based strategies for pest management by disrupting the reproductive processes.
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Affiliation(s)
- M N Rudra Gouda
- Division of Entomology, Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Sagar D
- Division of Genomic Resources, ICAR-National Bureau of Agricultural Insect Resources, Bengaluru, 275103, India
| | - Kishor Gaikwad
- Division of Molecular Biology and Biotechnology, ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India
| | - Ratna Prabha
- Agricultural Knowledge Management Unit (AKMU), ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Amrender Kumar
- Agricultural Knowledge Management Unit (AKMU), ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
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Brown NC, Gordon B, McDonough-Goldstein CE, Misra S, Findlay GD, Clark AG, Wolfner MF. The seminal odorant binding protein Obp56g is required for mating plug formation and male fertility in Drosophila melanogaster. eLife 2023; 12:e86409. [PMID: 38126735 PMCID: PMC10834028 DOI: 10.7554/elife.86409] [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: 01/24/2023] [Accepted: 12/20/2023] [Indexed: 12/23/2023] Open
Abstract
In Drosophila melanogaster and other insects, the seminal fluid proteins (SFPs) and male sex pheromones that enter the female with sperm during mating are essential for fertility and induce profound post-mating effects on female physiology. The SFPs in D. melanogaster and other taxa include several members of the large gene family known as odorant binding proteins (Obps). Work in Drosophila has shown that some Obp genes are highly expressed in the antennae and can mediate behavioral responses to odorants, potentially by binding and carrying these molecules to odorant receptors. These observations have led to the hypothesis that the seminal Obps might act as molecular carriers for pheromones or other compounds important for male fertility, though functional evidence in any species is lacking. Here, we used functional genetics to test the role of the seven seminal Obps in D. melanogaster fertility and the post-mating response (PMR). We found that Obp56g is required for male fertility and the induction of the PMR, whereas the other six genes are dispensable. We found males lacking Obp56g fail to form a mating plug in the mated female's reproductive tract, leading to ejaculate loss and reduced sperm storage, likely due to its expression in the male ejaculatory bulb. We also examined the evolutionary history of these seminal Obp genes, as several studies have documented rapid evolution and turnover of SFP genes across taxa. We found extensive lability in gene copy number and evidence of positive selection acting on two genes, Obp22a and Obp51a. Comparative RNAseq data from the male reproductive tract of multiple Drosophila species revealed that Obp56g shows high male reproductive tract expression in a subset of taxa, though conserved head expression across the phylogeny. Together, these functional and expression data suggest that Obp56g may have been co-opted for a reproductive function over evolutionary time.
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Affiliation(s)
- Nora C Brown
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Benjamin Gordon
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | | | - Snigdha Misra
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Geoffrey D Findlay
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
- Department of Biology, College of the Holy CrossWorcesterUnited States
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
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Brown NC, Gordon B, McDonough-Goldstein CE, Misra S, Findlay GD, Clark AG, Wolfner MF. The seminal odorant binding protein Obp56g is required for mating plug formation and male fertility in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.526941. [PMID: 36798169 PMCID: PMC9934574 DOI: 10.1101/2023.02.03.526941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
In Drosophila melanogaster and other insects, the seminal fluid proteins (SFPs) and male sex pheromones that enter the female with sperm during mating are essential for fertility and induce profound post-mating effects on female physiology and behavior. The SFPs in D. melanogaster and other taxa include several members of the large gene family known as odorant binding proteins (Obps). Previous work in Drosophila has shown that some Obp genes are highly expressed in the antennae and can mediate behavioral responses to odorants, potentially by binding and carrying these molecules to odorant receptors. These observations have led to the hypothesis that the seminal Obps might act as molecular carriers for pheromones or other compounds important for male fertility in the ejaculate, though functional evidence in any species is lacking. Here, we used RNAi and CRISPR/Cas9 generated mutants to test the role of the seven seminal Obps in D. melanogaster fertility and the post-mating response (PMR). We found that Obp56g is required for male fertility and the induction of the PMR, whereas the other six genes had no effect on fertility when mutated individually. Obp56g is expressed in the male's ejaculatory bulb, an important tissue in the reproductive tract that synthesizes components of the mating plug. We found males lacking Obp56g fail to form a mating plug in the mated female's reproductive tract, leading to ejaculate loss and reduced sperm storage. We also examined the evolutionary history of these seminal Obp genes, as several studies have documented rapid evolution and turnover of SFP genes across taxa. We found extensive lability in gene copy number and evidence of positive selection acting on two genes, Obp22a and Obp51a. Comparative RNAseq data from the male reproductive tract of multiple Drosophila species revealed that Obp56g shows high male reproductive tract expression only in species of the melanogaster and obscura groups, though conserved head expression in all species tested. Together, these functional and expression data suggest that Obp56g may have been co-opted for a reproductive function over evolutionary time.
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Affiliation(s)
- Nora C. Brown
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
| | - Benjamin Gordon
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
- Present address: Department of Physiology and Biophysics, University of Illinois College of Medicine, Chicago, IL, United States
| | | | - Snigdha Misra
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
- Present address: University of Petroleum and Energy Studies, Dehradun, UK, India
| | - Geoffrey D. Findlay
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
- Department of Biology, College of the Holy Cross, Worcester, MA, United States
| | - Andrew G. Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
| | - Mariana F. Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, United States
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Morimoto J, Barcellos R, Schoborg TA, Nogueira LP, Colaço MV. Assessing Anatomical Changes in Male Reproductive Organs in Response to Larval Crowding Using Micro-computed Tomography Imaging. NEOTROPICAL ENTOMOLOGY 2022; 51:526-535. [PMID: 35789989 PMCID: PMC9304064 DOI: 10.1007/s13744-022-00976-5] [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: 03/16/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Ecological conditions shape (adaptive) responses at the molecular, anatomical, and behavioral levels. Understanding these responses is key to predict the outcomes of intra- and inter-specific competitions and the evolutionary trajectory of populations. Recent technological advances have enabled large-scale molecular (e.g., RNAseq) and behavioral (e.g., computer vision) studies, but the study of anatomical responses to ecological conditions has lagged behind. Here, we highlight the role of X-ray micro-computed tomography (micro-CT) in generating in vivo and ex vivo 3D imaging of anatomical structures, which can enable insights into adaptive anatomical responses to ecological environments. To demonstrate the application of this method, we manipulated the larval density of Drosophila melanogaster Meigen flies and applied micro-CT to investigate the anatomical responses of the male reproductive organs to varying intraspecific competition levels during development. Our data is suggestive of two classes of anatomical responses which broadly agree with sexual selection theory: increasing larval density led to testes and ejaculatory duct to be overall larger (in volume), while the volume of accessory glands and, to a lesser extent, ejaculatory duct decreased. These two distinct classes of anatomical responses might reflect shared developmental regulation of the structures of the male reproductive system. Overall, we show that micro-CT can be an important tool to advance the study of anatomical (adaptive) responses to ecological environments.
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Affiliation(s)
- Juliano Morimoto
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
- Institute of Mathematics, University of Aberdeen, Aberdeen, UK.
- Programa de Pós-Graduação Em Ecologia E Conservação, Universidade Federal Do Paraná, Curitiba, Paraná, Brazil.
- Institute of Differential Geometry, Riemann Centre for Geometry and Physics, Leibniz Universität Hannover, Hannover, Germany.
| | - Renan Barcellos
- COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Todd A Schoborg
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
| | | | - Marcos Vinicius Colaço
- Laboratory of Applied Physics to Biomedical Sciences, Physics Institute, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Chen DS, Clark AG, Wolfner MF. Octopaminergic/tyraminergic Tdc2 neurons regulate biased sperm usage in female Drosophila melanogaster. Genetics 2022; 221:6637517. [PMID: 35809068 PMCID: PMC9339280 DOI: 10.1093/genetics/iyac096] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/07/2022] [Indexed: 02/07/2023] Open
Abstract
In polyandrous internally fertilizing species, a multiply-mated female can use stored sperm from different males in a biased manner to fertilize her eggs. The female's ability to assess sperm quality and compatibility is essential for her reproductive success, and represents an important aspect of postcopulatory sexual selection. In Drosophila melanogaster, previous studies demonstrated that the female nervous system plays an active role in influencing progeny paternity proportion, and suggested a role for octopaminergic/tyraminergic Tdc2 neurons in this process. Here, we report that inhibiting Tdc2 neuronal activity causes females to produce a higher-than-normal proportion of first-male progeny. This difference is not due to differences in sperm storage or release, but instead is attributable to the suppression of second-male sperm usage bias that normally occurs in control females. We further show that a subset of Tdc2 neurons innervating the female reproductive tract is largely responsible for the progeny proportion phenotype that is observed when Tdc2 neurons are inhibited globally. On the contrary, overactivation of Tdc2 neurons does not further affect sperm storage, release or progeny proportion. These results suggest that octopaminergic/tyraminergic signaling allows a multiply-mated female to bias sperm usage, and identify a new role for the female nervous system in postcopulatory sexual selection.
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Affiliation(s)
- Dawn S Chen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca NY 14853, USA
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca NY 14853, USA
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca NY 14853, USA
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Pu J, Wang Z, Cong H, Chin JSR, Justen J, Finet C, Yew JY, Chung H. Repression precedes independent evolutionary gains of a highly specific gene expression pattern. Cell Rep 2021; 37:109896. [PMID: 34706247 PMCID: PMC8578697 DOI: 10.1016/j.celrep.2021.109896] [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: 12/01/2020] [Revised: 08/24/2021] [Accepted: 10/06/2021] [Indexed: 12/12/2022] Open
Abstract
Highly specific expression patterns can be caused by the overlapping activities of activator and repressor sequences in enhancers. However, few studies illuminate how these sequences evolve in the origin of new enhancers. Here, we show that expression of the bond gene in the semicircular wall epithelium (swe) of the Drosophila melanogaster male ejaculatory bulb (EB) is controlled by an enhancer consisting of an activator region that requires Abdominal-B driving expression in the entire EB and a repressor region that restricts this expression to the EB swe. Although this expression pattern is independently gained in the distantly related Scaptodrosophila lebanonensis and does not require Abdominal-B, we show that functionally similar repressor sequences are present in Scaptodrosophila and also in species that do not express bond in the EB. We suggest that during enhancer evolution, repressor sequences can precede the evolution of activator sequences and may lead to similar but independently evolved expression patterns. Pu et al. show that the independent gain of a highly specific expression pattern across distantly related species may be because of the preexistence of repressor sequences that precedes the diversification of these species. This may reflect a general mechanism underlying the evolution of highly specific enhancers.
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Affiliation(s)
- Jian Pu
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.
| | - Zinan Wang
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA; Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI 48824, USA
| | - Haosu Cong
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Jacqueline S R Chin
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A(∗)STAR), Brenner Centre for Molecular Medicine, Singapore 117609, Singapore
| | - Jessa Justen
- Laboratory of Cellular and Molecular Biology, University of Wisconsin, Madison, WI 53706, USA
| | - Cédric Finet
- Yale-NUS College, 16 College Avenue West, Singapore 138527, Singapore
| | - Joanne Y Yew
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Henry Chung
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA; Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI 48824, USA.
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Divergence in Transcriptional and Regulatory Responses to Mating in Male and Female Fruitflies. Sci Rep 2019; 9:16100. [PMID: 31695054 PMCID: PMC6834580 DOI: 10.1038/s41598-019-51141-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/24/2019] [Indexed: 11/21/2022] Open
Abstract
Mating induces extensive physiological, biochemical and behavioural changes in female animals of many taxa. In contrast, the overall phenotypic and transcriptomic consequences of mating for males, hence how they might differ from those of females, are poorly described. Post mating responses in each sex are rapidly initiated, predicting the existence of regulatory mechanisms in addition to transcriptional responses involving de novo gene expression. That post mating responses appear different for each sex also predicts that the genome-wide signatures of mating should show evidence of sex-specific specialisation. In this study, we used high resolution RNA sequencing to provide the first direct comparisons of the transcriptomic responses of male and female Drosophila to mating, and the first comparison of mating-responsive miRNAs in both sexes in any species. As predicted, the results revealed the existence of sex- and body part-specific mRNA and miRNA expression profiles. More genes were differentially expressed in the female head-thorax than the abdomen following mating, whereas the opposite was true in males. Indeed, the transcriptional profile of male head-thorax tissue was largely unaffected by mating, and no differentially expressed genes were detected at the most stringent significance threshold. A subset of ribosomal genes in females were differentially expressed in both body parts, but in opposite directions, consistent with the existence of body part-specific resource allocation switching. Novel, mating-responsive miRNAs in each sex were also identified, and a miRNA-mRNA interactions analysis revealed putative targets among mating-responsive genes. We show that the structure of genome-wide responses by each sex to mating is strongly divergent, and provide new insights into how shared genomes can achieve characteristic distinctiveness.
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Meuti ME, Short SM. Physiological and Environmental Factors Affecting the Composition of the Ejaculate in Mosquitoes and Other Insects. INSECTS 2019; 10:E74. [PMID: 30875967 PMCID: PMC6468485 DOI: 10.3390/insects10030074] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/05/2019] [Accepted: 03/08/2019] [Indexed: 01/02/2023]
Abstract
In addition to transferring sperm, male mosquitoes deliver several proteins, hormones and other factors to females in their seminal fluid that inhibit remating, alter host-seeking behaviors and stimulate oviposition. Recently, bioinformatics, transcriptomics and proteomics have been used to characterize the genes transcribed in male reproductive tissues and the individual proteins that are delivered to females. Thanks to these foundational studies, we now understand the complexity of the ejaculate in several mosquito species. Building on this work, researchers have begun to identify the functions of various proteins and hormones in the male ejaculate, and how they mediate their effects on female mosquitoes. Here, we present an overview of these studies, followed by a discussion of an under-studied aspect of male reproductive physiology: the effects of biotic and abiotic factors on the composition of the ejaculate. We argue that future research in this area would improve our understanding of male reproductive biology from a physiological and ecological perspective, and that researchers may be able to leverage this information to study key components of the ejaculate. Furthermore, this work has the potential to improve mosquito control by allowing us to account for relevant factors when implementing vector control strategies involving male reproductive biology.
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Affiliation(s)
- Megan E Meuti
- Department of Entomology, The Ohio State University, 2001 Fyffe Rd., Room 232 Howlett Hall, Columbus, OH 43210, USA.
| | - Sarah M Short
- Department of Entomology, The Ohio State University, 2001 Fyffe Rd., Room 232 Howlett Hall, Columbus, OH 43210, USA.
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Koppik M, Specker JH, Lindenbaum I, Fricke C. Physiological Maturation Lags Behind Behavioral Maturation in Newly Eclosed Drosophila melanogaster Males. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2018; 91:399-408. [PMID: 30588207 PMCID: PMC6302630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The accessory gland (AG) produces seminal fluid proteins that are transferred to the female upon mating in many insects. These seminal fluid proteins often promote a male's post-copulatory reproductive success. Despite its crucial function many males eclose with a small gland not yet containing the full set of proteins. Thus, they need a physiological maturation period. Using Drosophila melanogaster, we tested whether this physiological maturation is linked to behavioral maturation in males and to what extent seminal fluid allocation patterns are influenced by physiological maturation. To that end, we measured AG protein content (as a proxy for physiological maturation) of young, immature males that were either successful in gaining a mating, but prevented from transferring seminal fluid proteins, or unsuccessful, thus using mating success as a proxy for behavioral maturation. Furthermore, we compared ejaculate allocation in immature and mature males in a single mating. Though mating success and gland maturation increase with male age, we found no evidence for a fine-tuned synchronization of behavioral and physiological maturation in males. This is especially surprising since we found reduced ejaculate allocation in very young, immature males, hinting at reduced fitness benefits from early matings in D. melanogaster.
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Affiliation(s)
- Mareike Koppik
- To whom all correspondence should be addressed: Mareike Koppik, Institute for Evolution and Biodiversity, University of Muenster, Huefferstrasse 1, 48149 Muenster, Germany; Tel: +492518321091, Fax: +492518324668,
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