The ZZ/ZW sex-determining mechanism originated twice and independently during evolution of the frog, Rana rugosa
The ZZ/ZW sex-determining mechanism originated twice and independently during evolution of the frog, Rana rugosa
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DOI：
10.1038/sj.hdy.6801068
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发表时间：
2008-01-01
期刊：
影响因子：
3.8
通讯作者：
Miura, I.
中科院分区：
文献类型：
--
作者：
Ogata, M.;Hasegawa, Y.;Miura, I.
日本蛙(Rana Rugosa)具有XX/XY和ZZ/ZW两种不同的性染色体类型。这两种类型是以局部群的形式发现的，在地理上被预测位于日本中部琵琶湖附近的边界区域隔开。为了确定这一精确的边界，通过对与性别相关的基因进行基因分型，对琵琶湖周围18个种群的异性恋进行了检查。利用线粒体12S rRNA基因分析了种群间的亲缘关系。结果表明，位于琵琶湖以东的铃鹿-基伊山脉将XX/XY种群与ZZ/ZW种群分开。出乎意料的是，从系统发育的角度来看，碧瓦湖周围的ZZ/ZW种群并不属于主要的ZW群，而是XY群。作者认为，琵琶湖周围的ZZ/ZW种群通过异性交配的性别变化，从XX/XY种群中分化出来，最终形成一个新的种群。这个团体因此被命名为“新ZW团体”。由于居住在日本西北部的主要ZW种群已知具有不同的男性异性恋起源，这一发现表明，在蛙的物种形成过程中，异性恋性别从男性到女性可能发生了两次独立的变化。
The Japanese frog, Rana rugosa, has two distinct sex chromosome types, XX/XY and ZZ/ZW. These two types are found in localized groups, separated geographically by a boundary area predicted to lie somewhere around Lake Biwa in central Japan. To determine this precise boundary, the heterogametic sex of 18 populations around Lake Biwa was examined by genotyping sex-linked genes. Phylogenetic relationships between the populations were also analyzed using mitochondrial 12S rRNA gene. Results showed that the Suzuka-Kii mountain range located east of Lake Biwa separated the XX/XY populations from the ZZ/ZW populations. Unexpectedly, from a phylogenetic perspective, the ZZ/ZW populations around Lake Biwa belonged not to the main ZW group but to the XY group. The authors propose that the ZZ/ZW populations around Lake Biwa diverged secondarily from the XX/XY group through a change of heterogametic sex, eventually forming a new group. This group was thus named the 'Neo-ZW group'. As the main ZW group inhabiting northwestern Japan is known to have a different male heterogametic origin, this finding shows that change of heterogametic sex from male to female may have occurred twice, and independently, during the frog speciation.