Genetic Characterization of Endangered Indian Mithun (Bos frontalis), Indian Bison/Wild Gaur (Bos gaurus) and Tho-tho Cattle (Bos indicus) Populations Using SSR Markers Reveals Their Diversity and Unique Phylogenetic Status

Abstract

Mithun (Bos frontalis) or gayal and Indian Bison or wild gaur (Bos gaurus) are listed among the rare and endangered bovine species of India. The remote location of mithun in four North Eastern Hill states (Arunachal Pradesh, Nagaland, Manipur, and Mizoram), scattered population size, and non-availability of genetic diversity status are major limitations towards devising a suitable breeding and conservation policy of these species. Since several studies have demonstrated the successful applicability of microsatellite/SSR markers across related genera/families in both crop plants and animal species, 30 FAO recommended cattle microsatellites were utilized for the assessment of the genetic diversity of Indian mithun, bison, and local Tho-tho cattle. Mitochondrial transmembrane protein coding cytochrome B (CYTB) complete sequence data of 71 bovine samples from India were also used to reinforce the study. Population structuring clustered the all bovines into three subgroups as per geographical location and species. Bottleneck analysis indicated a mode shift in the allelic frequency distribution of gaur, indicating minor genetic bottleneck events in the past, while no bottleneck was found in mithun and Tho-tho cattle. To our knowledge, this study represents the first report of molecular genetic characterization showing the population structure and status of genetic diversity in rare Indian bovines, namely, Mithun, Gaur, and Tho-tho cattle.