Independent Origin of XY and ZW Sex Determination Mechanisms in Mosquitofish Sister Species
Independent Origin of XY and ZW Sex Determination Mechanisms in Mosquitofish Sister Species
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DOI：
10.1534/genetics.119.302698
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发表时间：
2020-01-01
期刊：
影响因子：
3.3
通讯作者：
Schartl, Manfred
中科院分区：
文献类型：
--
作者：
Kottler, Verena A.;Feron, Romain;Schartl, Manfred
鱼类以其性别决定机制和性染色体系统的多样性而闻名。西部食蚊鱼（Gambusia affinis）和东部食蚊鱼（G. holbrooki）是姐妹种，它们的性别决定机制不同：G. affinis为ZZ/ZW， G. holbrooki为XX/XY。在这里，我们进行了限制性位点相关DNA （RAD-）和池测序（pool -seq）来表征这两个物种的性染色体。我们发现，雌性的ZW染色体和雄性的XY染色体对应于不同的连锁群，从而从不同的常染色体独立进化而来。在种间杂交种中，Y染色体优于W染色体，X染色体优于z染色体。在G. holbrooki中，我们发现了Y连锁黑色素沉着位点的候选区域，这是一种罕见的雄性表型，构成了潜在的性拮抗性状，并与其他此类特征（如体型大和攻击性行为）相关。我们在含有家族成员1的GIPC PDZ结构域y连锁等位基因（gipc1）上开发了一个基于snp的标记，该标记与所有被测试的G. holbrooki群体的黑色素病有关。这个基因座代表了一个颜色基因座的例子，它位于一个假定的性别决定因素附近，很可能在很大程度上促进了Y染色体的进化。
Fish are known for the outstanding variety of their sex determination mechanisms and sex chromosome systems. The western (Gambusia affinis) and eastern mosquitofish (G. holbrooki) are sister species for which different sex determination mechanisms have been described: ZZ/ZW for G. affinis and XX/XY for G. holbrooki. Here, we carried out restriction-site associated DNA (RAD-) and pool sequencing (Pool-seq) to characterize the sex chromosomes of both species. We found that the ZW chromosomes of G. affinis females and the XY chromosomes of G. holbrooki males correspond to different linkage groups, and thus evolved independently from separate autosomes. In interspecific hybrids, the Y chromosome is dominant over the W chromosome, and X is dominant over Z. In G. holbrooki, we identified a candidate region for the Y-linked melanic pigmentation locus, a rare male phenotype that constitutes a potentially sexually antagonistic trait and is associated with other such characteristics, e.g., large body size and aggressive behavior. We developed a SNP-based marker in the Y-linked allele of GIPC PDZ domain containing family member 1 (gipc1), which was linked to melanism in all tested G. holbrooki populations. This locus represents an example for a color locus that is located in close proximity to a putative sex determiner, and most likely substantially contributed to the evolution of the Y.