Abundant Genetic Diversity of Yunling Cattle Based on Mitochondrial Genome.

Simple Summary Mitochondrial DNA (mtDNA) analysis is a critical tool in assessing the maternal origin, phylogeny and population structure of domestic animals. Yunling cattle are a composite breed that was created by local Yunnan cattle breeds (as a maternal line) 30 years ago. It can be said that Yunling cattle represent important reservoirs of genetic diversity of local Yunnan cattle. Yunling cattle are characterized as a tropical/subtropical breed with fast growth, heat tolerance and parasite resistance, and can survive in a harsh environment and on low-quality roughage. Assessing the genetic characteristics of Yunling cattle is of particular importance for reasonable breeding strategies for Yunling cattle and the design of a local Yunnan cattle conservation program. Yunling cattle are a composite beef cattle breed, combining Brahman (1/2), Murray Grey (1/4) and Local Yunnan cattle (1/4), that was developed in Yunnan, China in the 1980s. Understanding the genetic information of Yunling cattle is of great significance to the development of reasonable breeding strategies for this breed. In the present study, we assessed the current genetic status of Yunling cattle in Yunnan Province (China) by analyzing the variability of the whole mitochondrial genome of 129 individuals. Altogether, 129 sequences displayed 47 different haplotypes. The haplotype diversity and the average number of nucleotide differences were 0.964 and 128.074, respectively. Phylogenetic analyses classified Yunling cattle into seven haplogroups: T1, T2, T3, T4, T6, I1 and I2. Haplogroup I1 was found to be predominant (41.86%), followed by T3 (28.68%). Furthermore, we also identified a novel haplogroup, T6, and defined the sub-haplogroup I1a in Yunling cattle. According to the formation process of Yunling cattle (local Yunnan cattle as the maternal line), the high genetic diversities in the mitochondria of Yunling cattle could be due to the complex maternal origin of local Yunnan cattle. Further studies about local Yunnan breeds are necessary to determine the exact source of haplogroup T6 in Yunling cattle. Our results will be useful for the evaluation and effective management of Yunling cattle.