Maternal Genetic Diversity Analysis of Guanling Cattle by Mitochondrial Genome Sequencing.

Owing to the unique geography and the isolated environment, Guanling cattle, which is one of five local cattle breeds in Guizhou, China, has developed unique characteristics. The number of pure Guanling cattle decreased markedly because of the hybridization with foreign breeds. In the present study, the maternal genetic diversity of 58 Guanling bulls was assessed by whole mitochondrial genome sequencing. Genetic polymorphisms and phylogenetic analyses classified Guanling cattle into two main lineages, where 43.10% of Guanling cattle were closely related to the foreign breeds and 56.90% displayed distinct features in mitochondrial genomic diversity. PCA analysis further separated Guanling cattle into four populations, one of which was clustered with the foreign breeds. The result of the structure plot and genetic polymorphisms revealed high genetic diversity within two populations that have a long genetic distance from the foreign breeds. Overall, our findings suggest that the whole mitochondrial genome sequencing analysis is a useful and reliable tool to study maternal genetic diversity and to identify the pure population of Guanling cattle. The results will be beneficial to the breeding management of Guanling cattle.