Maintenance of fertility in the face of meiotic drive

Selfish genetic elements that gain a transmission advantage through the destruction of sperm have grave implications for drive male fertility. In the X-linked SR meiotic drive system of a stalk-eyed fly, we found that drive males have greatly enlarged testes and maintain high fertility despite the destruction of half their sperm, even when challenged with fertilising large numbers of females. Conversely, we observed reduced allocation of resources to the accessory glands that probably explains the lower mating frequency of SR males. Body size and eyespan were also reduced, which are likely to impair viability and pre-copulatory success. We discuss the potential evolutionary causes of these differences between drive and standard males.通过破坏精子获取传递优势的自私遗传因子（selfish genetic elements），对减数分裂驱动（meiotic drive）型雄性的生育能力存在严重影响。在柄眼蝇（stalk-eyed fly）的X连锁SR减数分裂驱动系统中，我们发现驱动型雄性的睾丸显著增大；即便半数精子被破坏，其生育能力仍维持较高水平，即使在需要为大量雌性完成受精的压力条件下亦是如此。与之相反，驱动型雄性对附腺的资源分配有所减少，这或可解释其交配频率较低的现象。此外，驱动型雄性的体型与眼间距均出现缩小，这可能会削弱其生存能力与交配前的交配成功率。最后，我们针对驱动型雄性与标准型雄性之间上述差异的潜在进化成因展开了讨论。