Molecular approaches for conservation of endangered giant argali sheep (Ovis ammon) and dwarf blue sheep (Pseudois nayaur schaeferi) in Asia

Conservation of an endangered species requires knowledge of its evolutionary history, as well as the amount and distribution of genetic diversity existing in extant populations. Here, I used molecular genetic approaches to address conservation genetic issues for endangered argali sheep (Ovis ammon ) and dwarf blue sheep (Pseudois nayaur schaeferi) in Asia. First, I examined the phylogeography of 24 geographic populations of argali sheep throughout most of its distribution range using mtDNA control region sequences. Five major evolutionarily distinct lineages were revealed. Traditional morphology-based argali subspecific taxonomy received little support from these molecular analyses. I identified nine conservation units and propose that each unit be recognized as a genetically distinct subspecies. Results also suggest that argali originated in the Pamir region, and then spread to other regions through two paths of radiation. Second, I used both mtDNA control region sequence and nuclear microsatellites to study the population genetic structure of three argali populations in Mongolia. The mtDNA results revealed two evolutionarily distinct lineages, i.e., Altay population and Hangay/east Gobi populations. Microsatellite results indicated that the three populations are genetically distinct from each other, with approximately equal genetic differentiation and gene flow among them. I recommended two conservation units (Altay, and Hangay/east Gobi), and three management units (Altay, Hangay, and east Gobi) for conservation management. The effective population sizes estimated from genetic data were very similar to the results of field censuses, and suggest that these argali populations in Mongolia are relatively healthy. Third, I examined the genetic distinctiveness of highly endangered dwarf blue sheep by studying its phylogenetic relationship with blue sheep ( Pseudois nayaur) using mtDNA control region and Y-linked ZFY intron sequences. The mtDNA results revealed that dwarf blue sheep is a strongly supported monophyletic group with an average of 12.21% sequence divergence from blue sheep. ZFY intron results did not show dwarf blue sheep to be a monophyletic group, with a 0.51% sequence divergence and one shared haplotype. Therefore, I considered dwarf blue sheep to be a genetically distinct subspecies of blue sheep endemic to the upper Yangtze Gorge on the Tibetan Plateau.