X染色体减数分裂驱动(XCMD)在精子发生过程中杀死Y精子,导致自私X染色体的有偏差的传播。尽管这种强烈的传播,一些自然的XCMD系统保持在低而稳定的频率,而不是在人群中迅速传播。原因可能是男性携带者的健身能力下降,当他们失去一半的精子时,只生女儿,并且可能携带与XCMD相关的有害等位基因。因此,雌性可能会从避免与雄性携带者交配中受益,进一步降低了健康。XCMD的遗传抑制因子,阻止杀死Y精子并恢复正常的孟德尔遗传,也很常见,可以防止XCMD的传播。然而,被压抑的雄性是否像野生型雄性一样健康仍然是一个悬而未决的问题,因为很少考虑遗传抑制因子对雄性交配成功的影响。这里,我们调查了果蝇果蝇中XCMD雄性和受抑制的XCMD雄性与野生型雄性的交配能力,在发生驱动的野生种群中,驱动保持在20%的稳定频率。我们使用竞争性和非竞争性交配试验来评估该系统中的雄性交配成功。我们没有发现证据表明未受抑制的XCMD男性受到歧视。值得注意的是,然而,与野生型对照相比,它们抑制的XCMD对应物具有更高的雄性交配成功率。与野生型雄性相比,未抑制的XCMD雄性的后代产量降低了12%。这种成本似乎太弱,无法抵消XCMD的传输优势,因此,阻止XCMD传播的因素仍不清楚。
X chromosome meiotic drive (XCMD) kills Y-bearing sperm during spermatogenesis, leading to the biased transmission of the selfish X chromosome. Despite this strong transmission, some natural XCMD systems remain at low and stable frequencies, rather than rapidly spreading through populations. The reason may be that male carriers can have reduced fitness, as they lose half of their sperm, only produce daughters, and may carry deleterious alleles associated with XCMD. Thus, females may benefit from avoiding mating with male carriers, yielding a further reduction in fitness. Genetic suppressors of XCMD, which block the killing of Y sperm and restore fair Mendelian inheritance, are also common and could prevent the spread of XCMD. However, whether suppressed males are as fit as a wild-type male remains an open question, as the effect that genetic suppressors may have on a male\'s mating success is rarely considered. Here, we investigate the mating ability of XCMD males and suppressed XCMD males in comparison to wild-type males in the fruit fly Drosophila subobscura, where drive remains at a stable frequency of 20% in wild populations where it occurs. We use both competitive and non-competitive mating trials to evaluate male mating success in this system. We found no evidence that unsuppressed XCMD males were discriminated against. Remarkably, however, their suppressed XCMD counterparts had a higher male mating success compared to wild-type controls. Unsuppressed XCMD males suffered 12% lower offspring production in comparison to wild-type males. This cost appears too weak to counter the transmission advantage of XCMD, and thus the factors preventing the spread of XCMD remain unclear.