Zeng Bo, Xu Liu, Yue Bisong, Li Zhijun, Zou Fangdong
Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
Mol Phylogenet Evol. 2008 Aug;48(2):387-95. doi: 10.1016/j.ympev.2008.05.010. Epub 2008 May 14.
Within the genus Pseudois (Bovidae, Artiodactyla), two challenges are faced by taxonomists. First, the designation of the two subspecies of blue sheep, Pseudois nayaur nayaur and Pseudois nayaurszechuanensis, tends to be questionable with the accumulation of morphological and molecular data. Second, the taxonomic status of the dwarf blue sheep (Pseudois schaeferi) has been controversial since its discovery, and molecular analyses with relatively small sample sizes have not painted a clear picture. We collected samples and DNA sequence data from a broad geographic range in China to investigate the population structure of Pseudois nayaurszechuanensis and its phylogenetic relationship with Pseudois schaeferi. Employing mitochondrial cytochrome b and control region sequences, as well as the nuclear gene zona pellucida glycoprotein 3, further investigation was performed to extend upon previous studies. We found that the population of Helan Mountain of Ningxia Hui Autonomous Region has significantly differentiated from the populations in Qinghai, Gansu and Sichuan provinces, and may be classified as a new subspecies according to the 75% rule. The dwarf blue sheep was found to be some individuals of Pseudois nayaurszechuanensis with morphological variations and is not a species or subspecies, since they did not fall into a monophyletic group in the phylogenetic analyses with blue sheep. Gene flow between dwarf blue sheep and common blue sheep might have occurred in different areas of western Sichuan, which would result in the paraphyly of dwarf blue sheep.
在岩羊属（牛科，偶蹄目）中，分类学家面临两个挑战。第一，随着形态学和分子数据的积累，岩羊两个亚种，即指名亚种（Pseudois nayaur nayaur）和四川亚种（Pseudois nayaurszechuanensis）的划分往往存在疑问。第二，矮岩羊（Pseudois schaeferi）自发现以来，其分类地位一直存在争议，且样本量相对较小的分子分析也未能给出清晰的结果。我们从中国广泛的地理区域收集样本和DNA序列数据，以研究四川岩羊的种群结构及其与矮岩羊的系统发育关系。利用线粒体细胞色素b和控制区序列以及核基因透明带糖蛋白3，在以往研究的基础上进行了进一步调查。我们发现，宁夏回族自治区贺兰山的种群与青海、甘肃和四川省的种群有显著分化，根据75%规则，可能应划分为一个新亚种。结果发现，矮岩羊是四川岩羊中具有形态变异的一些个体，并非一个物种或亚种，因为在与岩羊的系统发育分析中，它们并未形成一个单系类群。矮岩羊和普通岩羊之间可能在四川西部的不同区域发生了基因流动，这导致了矮岩羊的并系性。
