Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA.
Proc Natl Acad Sci U S A. 2012 Feb 7;109(6):2043-8. doi: 10.1073/pnas.1121327109. Epub 2012 Jan 23.
In many species, both morphological and molecular traits related to sex and reproduction evolve faster in males than in females. Ultimately, rapid male evolution relies on the acquisition of genetic variation associated with differential reproductive success. Many newly evolved genes are associated with novel functions that might enhance male fitness. However, functional evidence of the adaptive role of recently originated genes in males is still lacking. The Sperm dynein intermediate chain multigene family, which encodes a Sperm dynein intermediate chain presumably involved in sperm motility, originated from complex genetic rearrangements in the lineage that leads to Drosophila melanogaster within the last 5.4 million years since its split from Drosophila simulans. We deleted all the members of this multigene family resident on the X chromosome of D. melanogaster by chromosome engineering and found that, although the deletion does not result in a reduction of progeny number, it impairs the competence of the sperm in the presence of sperm from wild-type males. Therefore, the Sperm dynein intermediate chain multigene family contributes to the differential reproductive success among males and illustrates precisely how quickly a new gene function can be incorporated into the genetic network of a species.
在许多物种中，与性别和繁殖相关的形态和分子特征在雄性中比在雌性中进化得更快。最终，雄性的快速进化依赖于获得与不同生殖成功相关的遗传变异。许多新进化的基因与可能增强雄性适应性的新功能相关。然而，最近起源的基因在雄性中的适应性作用的功能证据仍然缺乏。精子动力蛋白中间链多基因家族，编码一种精子动力蛋白中间链，可能参与精子运动，它起源于导致黑腹果蝇的谱系中的复杂遗传重排，自与拟果蝇分离以来，在过去的 540 万年里，它起源于黑腹果蝇的 X 染色体上。我们通过染色体工程删除了 D. melanogaster 上这个多基因家族的所有成员，发现尽管该缺失不会导致后代数量减少，但它会损害在存在野生型雄性精子时的精子能力。因此，精子动力蛋白中间链多基因家族有助于雄性之间的生殖成功差异，并精确地说明了新的基因功能可以多快被整合到物种的遗传网络中。
