Data from: Identification of sex-specific molecular markers using restriction site associated DNA sequencing (RAD-seq)

A major barrier to evolutionary studies of sex determination and sex chromosomes has been a lack of information on the types of sex-determining mechanisms that occur among different species. This is particularly problematic in groups where most species lack visually heteromorphic sex chromosomes, such as fish, amphibians and reptiles, because cytogenetic analyses will fail to identify the sex chromosomes in these species. We describe the use of restriction site associated DNA (RAD) sequencing, or RAD-seq, to identify sex-specific molecular markers and subsequently determine whether a species has male or female heterogamety. To test the accuracy of this technique we examined the lizard Anolis carolinensis. We performed RAD-seq on seven male and ten female A. carolinensis and found one male-specific molecular marker. Anolis carolinensis has previously been shown to possess male heterogamety and the recently published A. carolinensis genome facilitated characterization of the sex-specific RAD-seq marker. We validated the male specificity of the new marker using PCR on additional individuals and also found that it is conserved in some other Anolis species. We discuss the utility of using RAD-seq to identify sex determining mechanisms in other species with cryptic or homomorphic sex chromosomes and the implications for the evolution of male heterogamety in Anolis.

性别决定与性染色体的进化研究长期面临的核心障碍之一，是不同物种所采用的性别决定机制的相关信息严重匮乏。这一问题在多数物种缺乏肉眼可见异形性染色体（visually heteromorphic sex chromosomes）的类群中尤为突出——例如鱼类、两栖类与爬行类，因为此类物种无法通过细胞遗传学分析鉴定其性染色体。
本研究介绍了利用限制性酶切位点相关DNA测序（restriction site associated DNA sequencing，简称RAD-seq）鉴定性别特异性分子标记，并以此判断物种为雄性异配还是雌性异配性别决定系统的方法。为验证该技术的准确性，我们以卡罗莱纳安乐蜥（Anolis carolinensis）为研究对象：对7只雄性与10只雌性卡罗莱纳安乐蜥开展RAD-seq后，成功鉴定出1个雄性特异性分子标记。此前已有研究证实卡罗莱纳安乐蜥具备雄性异配性别决定系统，且近期公开的卡罗莱纳安乐蜥基因组也为该性别特异性RAD-seq标记的功能注释提供了重要助力。我们通过聚合酶链式反应（PCR）对额外个体进行验证，确认了该新标记的雄性特异性，同时发现该标记在部分其他安乐蜥属物种中存在保守性。本研究还探讨了RAD-seq技术在其他带有隐性感染色体或同形性染色体的物种中，用于鉴定性别决定机制的应用潜力，以及其对安乐蜥属雄性异配性别决定系统进化研究的启示。