Genetic relationships of five Indian horse breeds using microsatellite markers

The genetic relationships of five Indian horse breeds, namely Marwari, Spiti, Bhutia, Manipuri and Zanskari were studied using microsatellite markers. The DNA samples of 189 horses of these breeds were amplified by polymerase chain reaction using 25 microsatellite loci. The total number of alleles varied from five to 10 with a mean heterozygosity of 0.58 ± 0.05. Spiti and Zansakari were the most closely related breeds, whereas, Marwari and Manipuri were most distant apart with Nei's D_A genetic distance of 0.071 and 0.186, respectively. In a Nei's D_A genetic distances based neighbour joining dendrogram of these breeds and a Thoroughbred horse outgroup, the four pony breeds of Spiti, Bhutia, Manipuri and Zanskari clustered together and then with the Marwari breed. All the Indian breeds clustered independently from Thoroughbreds. The genetic relationships of Indian horse breeds to each other correspond to their geographical/environmental distribution.