7月2日发表在《自然》杂志上的一则研究显示，澳洲鬃狮蜥的野生种群容易受到气候变化的影响，出现性别反转。从前在蜥蜴中发现过从由染色体决定性别转变成由孵化时的温度决定性别的现象，但是这是第一次在野外环境中发现这样的现象。

澳大利亚堪培拉大学Clare E. Holleley和研究团队将131只成年蜥蜴在田野调查中获得的数据与受控的育种实验中的数据相结合。分子生物学分析表明，生活在该物种的适应温度范围偏高环境中的11只蜥蜴虽然性染色体是雄性，实际表现出来的性别是雌性，而且这些个体可以迅速从基因控制性别的系统转变到温度控制性别的系统。

当这些性反转了的雌性蜥蜴和正常的雌性蜥蜴交配后，它们的后代没有一个有性染色体，性别完全由蛋孵化时的温度决定。性反转的母亲生下的后代也更容易性别反转，强化了这种性别转变的趋势，而且其下的蛋的数量几乎是正常母亲的两倍，带来了更加雌性化的种群。

该研究还强调了极端气候在改变对于气候敏感的爬行动物的生物学和基因组方面的作用。在性别决定方式上有更大的灵活性可能是应对不可预知的气候的对抗手段，但还须进一步研究了解这种机制的真实成本和优势。（来源：中国科学报 唐凤）

Sex reversal triggers the rapid transition from genetic to temperature-dependent sex

Abstract  Sex determination in animals is amazingly plastic. Vertebrates display contrasting strategies ranging from complete genetic control of sex (genotypic sex determination) to environmentally determined sex (for example, temperature-dependent sex determination). Phylogenetic analyses suggest frequent evolutionary transitions between genotypic and temperature-dependent sex determination in environmentally sensitive lineages, including reptiles. These transitions are thought to involve a genotypic system becoming sensitive to temperature, with sex determined by gene–environment interactions. Most mechanistic models of transitions invoke a role for sex reversal. Sex reversal has not yet been demonstrated in nature for any amniote, although it occurs in fish6 and rarely in amphibians. Here we make the first report of reptile sex reversal in the wild, in the Australian bearded dragon (Pogona vitticeps), and use sex-reversed animals to experimentally induce a rapid transition from genotypic to temperature-dependent sex determination. Controlled mating of normal males to sex-reversed females produces viable and fertile offspring whose phenotypic sex is determined solely by temperature (temperature-dependent sex determination). The W sex chromosome is eliminated from this lineage in the first generation. The instantaneous creation of a lineage of ZZ temperature-sensitive animals reveals a novel, climate-induced pathway for the rapid transition between genetic and temperature-dependent sex determination, and adds to concern about adaptation to rapid global climate change.

原文链接：http://www.nature.com/nature/journal/v523/n7558/pdf/nature14574.pdf