Male eye span in stalk-eyed flies indicates genetic quality by meiotic drive suppression
Male eye span in stalk-eyed flies indicates genetic quality by meiotic drive suppression
复制标题
茎眼果蝇的雄性眼跨度通过减数分裂驱动抑制表明遗传质量
作者：
G. Wilkinson;Daven C. Presgraves;Lili Crymes
在某些物种中，雌性选择的配偶拥有预测后代生存的装饰品。然而，性选择的女性偏好男性的遗传质量仍然存在争议，因为传统的遗传机制保持不足的变化，男性质量占昂贵的偏好和装饰进化。在这里，我们表明，女性更喜欢的装饰品，表明性染色体之间的传输冲突所产生的遗传质量。通过比较柄眼蝇（Cyrtodiopsis）后代的性比分布，我们发现，雌性偏见的性比发生在物种表现出眼柄性二型性，和雌性偏好长眼跨度，。偏向雌性的性别比例是由减数分裂驱动造成的，这是一个“自私的”X染色体的优先传递。通过22个世代的人工选择，对性二型拟谷盗雄性眼柄长度进行了研究。达尔曼尼在复制系中产生较长的眼柄和偏向雄性的后代性别比。由于雄性偏向的后代性别比例发生时，驱动阻力Y染色体与驱动X染色体配对，长眼跨度与减数分裂驱动抑制基因。因此，男性的眼睛跨度通过影响后代的生殖价值来标志遗传质量。
In some species, females choose mates possessing ornaments that predict offspring survival. However, sexual selection by female preference for male genetic quality remains controversial because conventional genetic mechanisms maintain insufficient variation in male quality to account for costly preference and ornament evolution. Here we show that females prefer ornaments that indicate genetic quality generated by transmission conflict between the sex chromosomes. By comparing sex-ratio distributions in stalk-eyed fly (Cyrtodiopsis) progeny we found that female-biased sex ratios occur in species exhibiting eye-stalk sexual dimorphism, and female preferences for long eye span,. Female-biased sex ratios result from meiotic drive, the preferential transmission of a ‘selfish’ X-chromosome. Artificial selection for 22 generations on male eye-stalk length in sexually dimorphic C. dalmanni produced longer eye-stalks and male-biased progeny sex ratios in replicate lines. Because male-biased progeny sex ratios occur when a drive-resistant Y chromosome pairs with a driving X chromosome, long eye span is genetically linked to meiotic drive suppression. Male eye span therefore signals genetic quality by influencing the reproductive value of offspring.