Data from: Dmrt1 polymorphism and sex-chromosome differentiation in Rana temporaria

Sex-determination mechanisms vary both within and among populations of common frogs, opening opportunities to investigate the molecular pathways and ultimate causes shaping their evolution. We investigated the association between sex-chromosome differentiation (as assayed from microsatellites) and polymorphism at the candidate sex-determining gene Dmrt1 in two Alpine populations. Both populations harboured a diversity of X-linked and Y-linked Dmrt1 haplotypes. Some males had fixed male-specific alleles at all markers (“differentiated” Y chromosomes), others only at Dmrt1 (“proto-” Y chromosomes), while still others were genetically indistinguishable from females (undifferentiated X chromosomes). Besides these XX males, we also found rare XY females. The several Dmrt1 Y haplotypes differed in the probability of association with a differentiated Y chromosome, which we interpret as a result of differences in the masculinizing effects of alleles at the sex-determining locus. From our results, the polymorphism in sex-chromosome differentiation and its association with Dmrt1, previously inferred from Swedish populations, are not just idiosyncratic features of peripheral populations, but also characterize highly diverged populations in the central range. This implies that an apparently unstable pattern has been maintained over long evolutionary times.普通蛙种群内部及种群间的性别决定机制存在差异，这为探究塑造其演化历程的分子通路与根本成因提供了契机。本研究针对两个阿尔卑斯种群，探究了通过微卫星（microsatellites）检测得到的性别染色体分化，与候选性别决定基因Dmrt1的多态性之间的关联。两个种群均携带多种X连锁与Y连锁的Dmrt1单倍型。部分雄性在所有标记位点均携带固定的雄性特异性等位基因（即“分化型”Y染色体），部分仅在Dmrt1位点携带雄性特异性等位基因（即“原始型”Y染色体），还有部分在遗传层面与雌性无法区分（即未分化的X染色体）。除上述XX雄性外，本研究还发现了罕见的XY雌性个体。不同的Dmrt1 Y单倍型与分化型Y染色体产生关联的概率存在差异，我们将此归因于性别决定位点的等位基因在雄性化效应上的差异。基于本研究结果，此前在瑞典种群中推断得到的性别染色体分化多态性及其与Dmrt1的关联，并非仅为边缘种群的特有特征，同时也存在于分布中心区域的高度分化种群中。这表明，这种看似不稳定的模式在漫长的演化历程中得以持续维持。