Microsatellite marker-based estimation of the genetic diversity of cattle in Chongqing

Cattle are the main source of meat in Chongqing. This study investigated the genetic diversity of cattle native to Chongqing and 4 introduced breeds. A total of 96 individuals from 5 breeds were genotyped using six microsatellite markers. Five markers were highly polymorphic within the breed populations, and one marker had moderate levels of polymorphism. Heterozygosity ranged from 0.5379±0.0434 in Simmental to 0.6667±0.0559 in Charolais. The heterozygosity deficit was significant in all populations analyzed compared with the expected level of heterozygosity. In addition, two microsatellite markers (TGLA53 and OarFCB20) deviated from Hardy-Weinberg equilibrium across populations (except in cattle native to Chongqing). The mean number of alleles ranged from 6.00±2.37 in Angus to 7.17±2.14 in Droughtmaster across six markers. The coefficient of inbreeding ranged from 0.0017 in Simmental and Droughtmaster to 0.0367 in Angus. Pairwise difference analyses revealed that Simmental and Droughtmaster were the most differentiated (F_ST= 0.06861) from each other, whereas cattle native to Chongqing and Charolais were the least differentiated (F_ST= 0.00557). In summary, this study showed thatcattle native to Chongqing and 4 introduced breedswere genetically well protected in Chongqing, and information from this study would be helpful for guiding hybridization and genetic improvements in the future.