Department of Primatology, Max-Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig 04103, Germany.
BMC Evol Biol. 2012 Aug 21;12:150. doi: 10.1186/1471-2148-12-150.
The evolutionary relationships of closely related species have long been of interest to biologists since these species experienced different evolutionary processes in a relatively short period of time. Comparison of phylogenies inferred from DNA sequences with differing inheritance patterns, such as mitochondrial, autosomal, and X and Y chromosomal loci, can provide more comprehensive inferences of the evolutionary histories of species. Gibbons, especially the genus Hylobates, are particularly intriguing as they consist of multiple closely related species which emerged rapidly and live in close geographic proximity. Our current understanding of relationships among Hylobates species is largely based on data from the maternally-inherited mitochondrial DNAs (mtDNAs).
To infer the paternal histories of gibbon taxa, we sequenced multiple Y chromosomal loci from 26 gibbons representing 10 species. As expected, we find levels of sequence variation some five times lower than observed for the mitochondrial genome (mtgenome). Although our Y chromosome phylogenetic tree shows relatively low resolution compared to the mtgenome tree, our results are consistent with the monophyly of gibbon genera suggested by the mtgenome tree. In a comparison of the molecular dating of divergences and on the branching patterns of phylogeny trees between mtgenome and Y chromosome data, we found: 1) the inferred divergence estimates were more recent for the Y chromosome than for the mtgenome, 2) the species H. lar and H. pileatus are monophyletic in the mtgenome phylogeny, respectively, but a H. pileatus individual falls into the H. lar Y chromosome clade.
Based on the ~6.4 kb of Y chromosomal DNA sequence data generated for each of the 26 individuals in this study, we provide molecular inferences on gibbon and particularly on Hylobates evolution complementary to those from mtDNA data. Overall, our results illustrate the utility of comparative studies of loci with different inheritance patterns for investigating potential sex specific processes on the evolutionary histories of closely related taxa, and emphasize the need for further sampling of gibbons of known provenance.
由于这些物种在相对较短的时间内经历了不同的进化过程，因此密切相关的物种的进化关系长期以来一直引起生物学家的兴趣。比较具有不同遗传模式（如线粒体、常染色体、X 和 Y 染色体基因座）的 DNA 序列推断出的系统发育，可更全面地推断物种的进化历史。长臂猿，特别是 Hylobates 属，特别有趣，因为它们由多个迅速出现且生活在地理上非常接近的密切相关的物种组成。我们目前对 Hylobates 物种之间关系的了解主要基于来自母系遗传的线粒体 DNA (mtDNA)的数据。
为了推断长臂猿类的父系历史，我们从代表 10 个物种的 26 只长臂猿中测序了多个 Y 染色体基因座。正如预期的那样，我们发现序列变异水平比线粒体基因组（mtgenome）低五倍。尽管我们的 Y 染色体系统发育树与 mtgenome 树相比分辨率相对较低，但我们的结果与 mtgenome 树所暗示的长臂猿属的单系性一致。在比较 mtgenome 和 Y 染色体数据的分化分子年代测定和系统发育树的分支模式时，我们发现：1）对于 Y 染色体而言，推断的分歧估计比 mtgenome 更为近期，2）在 mtgenome 系统发育树上，H. lar 和 H. pileatus 分别是单系的，但一个 H. pileatus 个体属于 H. lar 的 Y 染色体分支。
基于本研究中每个个体产生的约 6.4kb 的 Y 染色体 DNA 序列数据，我们提供了关于长臂猿的分子推断，特别是对 Hylobates 进化的推断，这些推断与 mtDNA 数据的推断相辅相成。总体而言，我们的结果说明了比较具有不同遗传模式的基因座的研究对于研究密切相关分类群的进化历史中潜在的性别特异性过程具有实用价值，并强调需要进一步对具有已知来源的长臂猿进行采样。
