Interactions among thermal parameters determine offspring sex under temperature-dependent sex determination
Interactions among thermal parameters determine offspring sex under temperature-dependent sex determination
复制标题
DOI：
10.1098/rspb.2010.1040
复制
发表时间：
2011-01
期刊：
影响因子：
--
通讯作者：
D. Warner;R. Shine
中科院分区：
文献类型：
--
作者：
D. Warner;R. Shine
在许多动物中，胚胎发育所经历的温度决定了后代的性别（例如温度依赖性性别决定，TSD），但大多数研究严格关注平均温度的影响，很少强调温度波动的重要性。在Jacky龙（Amphibolurus muricatus），澳大利亚蜥蜴TSD，数据从巢在外地表明，后代的性别比例是可预测的热波动，但不是从平均巢温度。为了澄清这个悖论，我们在两个水平的平均温度和三个水平的昼夜波动的析因实验中孵化鸡蛋。我们表明，后代的性别是由这些关键的热参数之间的相互作用。有趣的是，由于这两个热描述符在整个孵化季节向相反的方向移动，这种相互作用的影响抑制了性别比例的季节性变化。因此，我们的研究结果表明，TSD可以产生后代的性别比例，类似于那些基因型性别决定系统下产生的。这些发现提出了重要的考虑因素，了解TSD反应规范的多样性，设计实验，评估TSD的进化意义，并预测性别比例在过去和未来的气候变化情景。
In many animals, temperatures experienced by developing embryos determine offspring sex (e.g. temperature-dependent sex determination, TSD), but most studies focus strictly on the effects of mean temperature, with little emphasis on the importance of thermal fluctuations. In the jacky dragon (Amphibolurus muricatus), an Australian lizard with TSD, data from nests in the field demonstrate that offspring sex ratios are predictable from thermal fluctuations but not from mean nest temperatures. To clarify this paradox, we incubated eggs in a factorial experiment with two levels of mean temperature and three levels of diel fluctuation. We show that offspring sex is determined by an interaction between these critical thermal parameters. Intriguingly, because these two thermal descriptors shift in opposing directions throughout the incubation season, this interactive effect inhibits seasonal shifts in sex ratio. Hence, our results suggest that TSD can yield offspring sex ratios that resemble those produced under genotypic sex-determining systems. These findings raise important considerations for understanding the diversity of TSD reaction norms, for designing experiments that evaluate the evolutionary significance of TSD, and for predicting sex ratios under past and future climate change scenarios.