Haus Tanja, Roos Christian, Zinner Dietmar
Cognitive Ethology Laboratory and Primate Genetics Laboratory, German Primate Center, Leibniz Institute for Primate Research, 37077 Göttingen, Germany ; Centre of Biodiversity and Sustainable Land Use, Georg-August-University, 37075 Göttingen, Germany.
Int J Primatol. 2013;34(5):986-999. doi: 10.1007/s10764-013-9717-5. Epub 2013 Sep 14.
Introgressive hybridization may cause substantial discordances among phylogenies based on different genetic markers. Such discordances have been found in diverse mammal species including primates. A recent study of mitochondrial DNA (mtDNA) revealed several poly- and paraphyletic relationships in African green monkeys (), suggesting contemporary and/or ancient introgressive hybridization among almost all parapatric species of the genus. However, mtDNA analyses alone do not allow us to draw conclusions concerning introgression events. In this study we analyzed two Y chromosomal (Y-chr) markers for 30 African green monkey samples and compared the resulting genetic relationships to those based on published mtDNA data. In line with the results for mtDNA, we found no Y-chr evidence of hypothesized hybridization among and in the northern part of the contact zone in West Africa, and we found two distinct and distantly related Y-chr haplotypes within the range of , suggesting possible cryptic genetic diversity rather than ancient introgressive hybridization in this species. In contrast, Y-chr data revealed monophyletic relationships within from East Africa, suggesting that mtDNA paraphylies found in this species are most likely to be the result of ancient introgressive hybridization and subsequent cytonuclear extinction of an earlier taxon. Our results accentuate the importance of analyzing sex chromosomal data in addition to mtDNA to obtain more information on the potential outcomes of hybridization with respect to genetic and species diversity. Analysis of more diverse nuclear marker sets is needed to obtain a more complete picture of the African green monkey evolution.
渐渗杂交可能会导致基于不同遗传标记的系统发育之间出现显著不一致。这种不一致在包括灵长类动物在内的多种哺乳动物中都有发现。最近一项关于线粒体DNA（mtDNA）的研究揭示了非洲绿猴中的几种多系和并系关系，这表明该属几乎所有邻域分布物种之间存在当代和/或古代的渐渗杂交。然而，仅靠mtDNA分析无法让我们得出关于渐渗事件的结论。在本研究中，我们分析了30个非洲绿猴样本的两个Y染色体（Y-chr）标记，并将所得的遗传关系与基于已发表的mtDNA数据的关系进行了比较。与mtDNA的结果一致，我们在西非接触区北部的[物种名称1]和[物种名称2]之间没有发现Y染色体证据支持假设的杂交，并且在[物种名称3]的分布范围内发现了两种不同且亲缘关系较远的Y染色体单倍型，这表明该物种可能存在隐秘的遗传多样性，而非古代渐渗杂交。相比之下，Y染色体数据揭示了东非[物种名称4]内部的单系关系，这表明该物种中发现地mtDNA并系很可能是古代渐渗杂交以及随后一个早期分类单元的细胞核-细胞质灭绝的结果。我们的结果强调了除mtDNA外分析性染色体数据对于获取关于杂交在遗传和物种多样性方面潜在结果的更多信息的重要性。需要分析更多样化的核标记集来更全面地了解非洲绿猴的进化。
