Genetic diversity and bottleneck analysis of sheep based on microsatellite markers

Abstract

The genetic diversity of Madras Red sheep at Post Graduate Research Institute in Animal Sciences, Kattupakkam (Tamil Nadu) and Mecheri sheep at Mecheri Sheep Research Station, Pottaneri (Tamil Nadu) was analysed using FAO recommended microsatellite markers. Genetic variation at 10 microsatellite loci, population structure and genetic bottleneck analysis were done to provide genetic information. A total of 98 and 86 alleles were scored for Madras Red and Mecheri sheep, respectively. The polymorphism information content ranged from 0.609 to 0.902 for all the microsatellite loci. The overall observed and estimated heterozygosity for all loci combined were 0.972 and 0.785 for Madras Red and 0.982 and 0.774 for Mecheri sheep, respectively. The average and total heterozygosity of subpopulation was 0.779 and 0.821, respectively. The coefficient of gene differentiation was 0.049 between the breeds which indicates that the genetic diversity is low between the Madras Red and Mecheri breeds of sheep with respect to microsatellite loci studied. The study revealed no genetic bottleneck in recent past and this was confirmed by mode shift test which gave L-shaped distribution for proportion of alleles, indicating that the population is stable with respect to population size. The panel of microsatellites used was highly informative for molecular characterization and could be used for exploitation of genetic diversity of the related breeds for conservation.