奇特的动物基因组与脊椎动物性别及性染色体的演化

Weird animal genomes and the evolution of vertebrate sex and sex chromosomes.

作者信息

Marshall Graves Jennifer A

机构信息

Research School of Biological Science, The Australian National University, Canberra, ACT 2601, Australia.

出版信息

Annu Rev Genet. 2008;42:565-86. doi: 10.1146/annurev.genet.42.110807.091714.

DOI:10.1146/annurev.genet.42.110807.091714

PMID:18983263

Abstract

Humans, mice, and even kangaroos have an XX female:XY male system of sex determination, in which the Y harbors a male-dominant sex-determining gene SRY. Birds have the opposite, ZZ males and ZW females, and may use a dosage-sensitive Z-borne gene. Other reptiles have genetic sex but no visible sex chromosomes, or determine sex by temperature of egg incubation. How can we make sense of so much variation? How do systems change in evolution? Studies of some unlikely animals-platypus and dragon lizards, frogs and fish-confirm that evolutionary transitions have occurred between TSD and GSD systems, between XY and ZW systems, and even between male and female heterogametic systems. Here I explore nonmodel systems that offer some new perspectives on some venerable questions of sex and sex chromosomes.

摘要

人类、小鼠甚至袋鼠都有XX为雌性、XY为雄性的性别决定系统，其中Y染色体携带一个雄性主导的性别决定基因SRY。鸟类则相反，ZZ为雄性，ZW为雌性，可能使用一个剂量敏感的Z染色体基因。其他爬行动物有遗传性别，但没有可见的性染色体，或者通过卵孵化的温度来决定性别的。我们如何理解如此多的变异？这些系统在进化过程中是如何变化的？对一些不太可能的动物——鸭嘴兽、飞龙蜥蜴、青蛙和鱼类——的研究证实，TSD（温度依赖型性别决定）和GSD（遗传性别决定）系统之间、XY和ZW系统之间，甚至在雄性和雌性异配性别系统之间都发生了进化转变。在这里，我探讨了一些非模式系统，这些系统为一些关于性别和性染色体的古老问题提供了一些新的视角。