Helleu Quentin, Gérard Pierre R, Montchamp-Moreau Catherine
Laboratoire Évolution Génomes et Spéciation, CNRS UPR9034, Gif-sur-Yvette, France and Université Paris-Sud, Orsay, France.
Cold Spring Harb Perspect Biol. 2014 Dec 18;7(2):a017616. doi: 10.1101/cshperspect.a017616.
Sex chromosome drivers are selfish elements that subvert Mendel's first law of segregation and therefore are overrepresented among the products of meiosis. The sex-biased progeny produced then fuels an extended genetic conflict between the driver and the rest of the genome. Many examples of sex chromosome drive are known, but the occurrence of this phenomenon is probably largely underestimated because of the difficulty to detect it. Remarkably, nearly all sex chromosome drivers are found in two clades, Rodentia and Diptera. Although very little is known about the molecular and cellular mechanisms of drive, epigenetic processes such as chromatin regulation could be involved in many instances. Yet, its evolutionary consequences are far-reaching, from the evolution of mating systems and sex determination to the emergence of new species.
性染色体驱动因子是一类自私元件,它们破坏孟德尔第一分离定律,因此在减数分裂产物中占比过高。由此产生的性别偏向后代进而加剧了驱动因子与基因组其他部分之间的长期遗传冲突。已知许多性染色体驱动的例子,但由于难以检测,这种现象的实际发生率可能被大大低估了。值得注意的是,几乎所有的性染色体驱动因子都存在于两个进化枝中,即啮齿目和双翅目。尽管对驱动的分子和细胞机制了解甚少,但在许多情况下,诸如染色质调控等表观遗传过程可能与之有关。然而,其进化后果影响深远,从交配系统的进化、性别决定到新物种的出现。