Genetic variation and divergence among swamp buffalo, river buffalo and cattle: A microsatellite survey on five populations in China

Domestic buffalo and cattle are two extremely important livestock species in worldwide agricultural production. In this paper, to investigate genetic diversity and divergence among swamp buffalo, river buffalo and cattle. 30 microsatellite markers were screened on 168 individuals sampled from five populations. Substantial differences were observed among the three groups of animals with respect to allele frequency distribution. allele size and polymorphism. The cattle sample (Mongolian) showed significantly higher genetic variability (0.674 of gene diversity, p < 0.01), and the swamp and river buffalo samples displayed similar degree of genetic variation (0.536 in swamp and 0.546 in river, p = 0.92). Results of both phylogenetic tree and multivariate analysis could distinguish three groups of animals, suggesting thcir deep evolutionary divergence. Additionally. using (delta mu)(2) genetic distance, we estimated a divergence time of 1.7 million years between swamp and river buffalo that strongly supported distinct genetic origins for the two buffalo types.