Hurst L D
Heredity (Edinb). 1994 Sep;73 ( Pt 3):233-43. doi: 10.1038/hdy.1994.128.
The mammalian Y chromosome may be an attractor for selfish growth factors. A suppressor of the selfish growth effects would be expected to spread were it to have an appropriate parent-specific expression rule. A suppressor could act by boosting the resource demands of competing female embryos. This possibility may explain incidences of the escape from X-inactivation and provides a rationale for why these genes typically have Y-linked homologues. Alternatively, a suppressor could act to decrease the resource demands of males with the selfish Y. This possibility is supported by the finding that the size of male, but not female, human infants is negatively correlated to the number of X chromosomes. A protracted arms race between a selfish gene and its suppressor may ensue. Both the variation in copy number of Zfy and the unusually fast sequence evolution of Sry may be explained by such an arms race. As required by the model, human Sry is known to have an X-linked suppressor. Preliminary evidence suggests that, as predicted, rapid sequence evolution of Sry may be correlated with female promiscuity. The case for fast sequence evolution as the product of maternal/foetal conflict is strengthened by consideration of the rapid evolution of placental lactogens in both ruminants and rodents.
哺乳动物的Y染色体可能是自私生长因子的吸引对象。如果一个抑制自私生长效应的因子具有合适的亲本特异性表达规则，那么它有望得以传播。一个抑制因子可以通过增加竞争的雌性胚胎的资源需求来发挥作用。这种可能性或许可以解释X染色体失活逃逸的现象，并为这些基因通常具有Y连锁同源物提供了一个理论依据。或者，一个抑制因子可以通过减少具有自私Y染色体的雄性的资源需求来发挥作用。男性（而非女性）婴儿的体型与X染色体数量呈负相关这一发现支持了这种可能性。自私基因与其抑制因子之间可能会随之展开一场持久的军备竞赛。Zfy拷贝数的变化以及Sry异常快速的序列进化都可以用这样一场军备竞赛来解释。正如该模型所要求的，已知人类的Sry有一个X连锁抑制因子。初步证据表明，正如所预测的那样，Sry的快速序列进化可能与雌性滥交有关。通过考虑反刍动物和啮齿动物中胎盘催乳素的快速进化，快速序列进化作为母体/胎儿冲突产物的证据得到了加强。
