Feng J, Lajia C, Taylor D J, Webster M S
Department of Biological Sciences, State University of New York at Buffalo, 14260, USA.
J Hered. 2001 Jan-Feb;92(1):9-15. doi: 10.1093/jhered/92.1.9.
To elucidate the controversial systematic relationship of blue sheep (Pseudois nayaur) and endangered dwarf blue sheep, we sequenced part of the mtDNA control region and Y-linked ZFY intron, and carried out phylogenetic analyses. Mitochondrial results revealed that the dwarf blue sheep is a strongly supported monophyletic group, with an average of 12.21% sequence divergence from the blue sheep. This is the first genetic evidence for the distinctness of the dwarf blue sheep. ZFY intron results showed an average of 0.51% sequence divergence, and one shared haplotype between the dwarf blue sheep and blue sheep. By analyzing an expanded data set that incorporated ZFY intron sequences of two additional Ovis (sheep) species-O. nivicola and O. ammon--we demonstrated that ZFY intron provides good resolution at the species and genus levels. The ZFY intron sequence divergence between dwarf blue sheep and blue sheep was comparable to that within the two Ovis species. Moreover, we found intraspecific sequence variation in ZFY intron for all three species examined. We propose that dwarf blue sheep be designated as a subspecies of blue sheep, P. n. schaeferi.
为阐明岩羊（Pseudois nayaur）与濒危矮岩羊之间存在争议的系统发育关系，我们对线粒体DNA控制区的部分序列和Y染色体连锁的ZFY内含子进行了测序，并开展了系统发育分析。线粒体分析结果显示，矮岩羊是一个得到有力支持的单系类群，与岩羊的平均序列差异为12.21%。这是矮岩羊独特性的首个遗传学证据。ZFY内含子分析结果显示平均序列差异为0.51%，且矮岩羊与岩羊之间存在一个共享单倍型。通过分析一个纳入了另外两种绵羊属（Ovis）物种——雪羊（O. nivicola）和盘羊（O. ammon）——的ZFY内含子序列的扩展数据集，我们证明ZFY内含子在物种和属水平上具有良好的分辨率。矮岩羊与岩羊之间的ZFY内含子序列差异与两种绵羊属物种内部的差异相当。此外，我们在所研究的所有三个物种的ZFY内含子中均发现了种内序列变异。我们建议将矮岩羊定为岩羊的一个亚种，即P. n. schaeferi。
