Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria
Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria
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DOI：
10.1186/1471-2156-9-3
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发表时间：
2008-01-08
期刊：
影响因子：
2.9
通讯作者：
Merilae, Juha
中科院分区：
文献类型：
--
作者：
Matsuba, Chikako;Miura, Ikuo;Merilae, Juha
背景资料：了解特定物种的性别比例动态需要了解其性别决定系统，以及在不同生命阶段获得可靠的性别鉴定工具。与其他两栖动物一样，普通青蛙（Rana temporaria）没有分化良好的性染色体，个体遗传性别的鉴定可能会因性别逆转而变得复杂。在这里，我们报告的研究结果，阐明性别决定系统和性别比例的变化，在这species.Results：微卫星位点RtSB 03被发现是性连锁的四个地理上不同的群体，这表明男性异配常见的青蛙。然而，在其他三个群体的检查，没有或很少的证据表明，性连锁检测到正在进行的/最近的重组事件，和/或频繁的性别逆转。比较RtSB 03等位基因的遗传模式和同胞内表型性别，发现性别连锁的混合证据：在一个群体中，所有具有男性表型的个体都携带一个男性特异等位基因，而在另一个群体中，结果更加混合。这些结果只有在我们假设RtSB 03基因座与某些但不是所有常见青蛙种群中的雄性性别决定因子连锁时才有意义，以及是否经常发生表型性别逆转--这一点在该物种中有较早的证据。
Background: Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species.Results: A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population.Conclusion: These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals - for which there is earlier evidence from this species - are frequently occurring.