Genetics of sex determination in tilapiine species
Genetics of sex determination in tilapiine species
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DOI：
10.1159/000117718
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发表时间：
2008-01-01
影响因子：
2.3
通讯作者：
Kocher, T. D.
中科院分区：
文献类型：
--
作者：
Cnaani, A.;Lee, B. -Y.;Kocher, T. D.
我们在六种密切相关的罗非鱼物种中鉴定出与性别决定基因相关的 DNA 标记。性别决定的方式因物种而异。 Oreochromis karongae 和 Tilapia mariae 的性别决定基因座位于连锁群 (LG) 3 上，雌性是异配的（WZ-ZZ 系统）。在 O. niloticus 和 T. zillii 中，性别决定基因座位于 LG1 上，并且雄性是异配的（XX-XY 系统）。在金黄色葡萄球菌和莫桑比克酵母中观察到更复杂的模式，其中 LG1 和 LG3 上的标记都与性别相关。我们发现了 LG1 与性别相关的致死效应的证据，以及两个连锁群中基因座之间的相互作用。遗传图谱和物理图谱的比较表明，LG3 上存在一个广泛的重组抑制区域，其中包含性别决定基因座。在雌性异配性别中发现了性别特异性重组抑制。序列分析显示该区域重复元素的积累。系统发育分析表明，该进化枝中至少发生了两次性别决定模式的转变。密切相关的物种之间性别决定机制的这种差异使罗非鱼成为研究脊椎动物性染色体进化的优秀模型系统。版权所有 (c) 2008 S. Karger AG，巴塞尔
We identified DNA markers linked to sex determining genes in six closely related species of tilapiine fishes. The mode of sex determination differed among species. In Oreochromis karongae and Tilapia mariae the sex-determining locus is on linkage group (LG) 3 and the female is heterogametic ( WZ-ZZ system). In O. niloticus and T. zillii the sex-determining locus is on LG1 and the male is heterogametic ( XX- XY system). A more complex pattern was observed in O. aureus and O. mossambicus, in which markers on both LG1 and LG3 were associated with sex. We found evidence for sex-linked lethal effects on LG1, as well as interactions between loci in the two linkage groups. Comparison of genetic and physical maps demonstrated a broad region of recombination suppression harboring the sex-determining locus on LG3. Sex-specific recombination suppression was found in the female heterogametic sex. Sequence analysis showed the accumulation of repetitive elements in this region. Phylogenetic analysis suggests that at least two transitions in the mode of sex determination have occurred in this clade. This variation in sex determination mechanisms among closely related species makes tilapias an excellent model system for studying the evolution of sex chromosomes in vertebrates. Copyright (c) 2008 S. Karger AG, Basel