Sexual reproduction may pose myriad short-term costs to females. Despite these costs, sexual reproduction is near ubiquitous. Facultative parthenogenesis is theorized to mitigate some of the costs of sex, as individuals can participate in occasional sex to limit costs while obtaining many benefits. However, most theoretical models assume sexual reproduction is fixed following mating, with no possibility of clutches of mixed reproductive ontogeny. Therefore, we asked: if coercive males are present at high frequency in a population of facultative parthenogens, will their clutches be solely sexually produced, or will there be evidence of sexually and asexually-produced offspring? How will their offspring production compare to conspecifics in low-frequency male populations? We addressed our questions by collecting females and egg clutches of the facultatively parthenogenetic Opiliones species Leiobunum manubriatum and L. globosum. In L. manubriatum, females from populations with few males were not significantly more fecund than females from populations with higher male relative frequency, despite the potential release of the former from sexual conflict. We used 3 genotyping methods along with a custom set of DNA capture probes to reveal that offspring of L. manubriatum from these high male populations were primarily produced via asexual reproduction. This is surprising because sex ratios in these southern populations approach equality, increasing the probability for females to encounter mates and produce offspring sexually. We additionally found evidence for reproductive polymorphisms within populations. Rapid and accurate SNP genotyping data will continue to allow us to address broader evolutionary questions regarding the role of facultative reproductive modes in the maintenance of sex.

中文翻译：

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兼性孤雌雄蕊生殖方式的基因组决定

有性生殖可能会给女性带来无数的短期成本。尽管有这些成本，但有性生殖几乎无处不在。从理论上讲，兼性孤雌生殖可以减轻一些性行为的成本，因为个人可以偶尔参与性行为以限制成本，同时获得许多好处。然而，大多数理论模型假设有性生殖在交配后是固定的，不可能发生混合生殖个体发育。因此，我们问：如果在兼性孤雌生殖种群中高频率地存在胁迫性雄性，它们的生殖器是否仅通过性产生？还是有性和无性产生的后代的证据？他们的后代生产与低频男性群体中的同种相比如何？我们通过收集兼性孤雌生殖 Opiliones 物种 Leiobunum manubriatum 和 L. globosum 的雌性和卵子来解决我们的问题。在 L. manubriatum 中，来自雄性较少种群的雌性并不比来自雄性相对频率较高的种群的雌性显着更多，尽管前者可能会从性冲突中释放出来。我们使用 3 种基因分型方法以及一组定制的 DNA 捕获探针来揭示来自这些高雄性种群的 L. manubriatum 的后代主要是通过无性繁殖产生的。这令人惊讶，因为这些南方人口的性别比例接近平等，增加雌性遇到配偶并通过性行为产生后代的可能性。我们还发现了种群内生殖多态性的证据。快速准确的 SNP 基因分型数据将继续使我们能够解决关于兼性生殖模式在维持性别中的作用的更广泛的进化问题。