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Reproductive traits that influence female remating and competitive fertilization rapidly evolve in response to sexual selection and sexual conflict. One such trait, observed across diverse animal taxa, is the formation of a structural plug inside the female reproductive tract (FRT), either during or shortly after mating. In Drosophila melanogaster , male seminal fluid forms a mating plug inside the female bursa, which has been demonstrated to influence sperm entry into storage and latency of female remating. Processing of the plug, including its eventual ejection from the female's reproductive tract, influences the competitive fertilization success of her mates and is mediated by female × male genotypic interactions. However, female contributions to plug formation and processing have received limited attention. Using developmental mutants that lack glandular FRT tissues, we reveal that these tissues are essential for mating plug ejection. We further use proteomics to demonstrate that female glandular proteins, and especially proteolytic enzymes, contribute to mating plug composition and have a widespread impact on plug formation and composition. Together, these phenotypic and molecular data identify female contributions to intersexual interactions that are a potential mechanism of post-copulatory sexual selection.
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Proteomic diversification of spermatostyles among six species of whirligig beetles
Abstract Seminal fluid protein composition is complex and commonly assumed to be rapidly divergent due to functional interactions with both sperm and the female reproductive tract (FRT), both of which evolve rapidly. In addition to sperm, seminal fluid may contain structures, such as mating plugs and spermatophores. Here, we investigate the evolutionary diversification of a lesser‐known ejaculate structure: the spermatostyle, which has independently arisen in several families of beetles and true bugs. We characterized the spermatostyle proteome, in addition to spermatostyle and FRT morphology, in six species of whirligig beetles (family Gyrinidae). Spermatostyles were enriched for proteolytic enzymes, and assays confirmed they possess proteolytic activity. Sperm‐leucylaminopeptidases (S‐LAPs) were particularly abundant, and their localization to spermatostyles was confirmed by immunohistochemistry. Although there was evidence for functional conservation of spermatostyle proteomes across species, phylogenetic regressions suggest evolutionary covariation between protein composition and the morphology of both spermatostyles and FRTs. We postulate that S‐LAPs (and other proteases) have evolved a novel structural role in spermatostyles and discuss spermatostyles as adaptations for delivering male‐derived materials to females.
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- Award ID(s):
- 2011045
- PAR ID:
- 10546023
- Publisher / Repository:
- Wiley Periodicals LLC
- Date Published:
- Journal Name:
- Molecular Reproduction and Development
- Volume:
- 91
- Issue:
- 5
- ISSN:
- 1040-452X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/mrd.23745
