Vol. 10, Special Issue 5 (2021)

Author(s):
Radhika G, Aravindakshan TV and Stephy Thomas

Abstract:
Assessing the variation in domestic animals through genetic diversity analysis, forms the basis for sustainable management and development of Farm Animal Genetic Resources. Microsatellites, which were reported to be highly polymorphic and widely distributed throughout the genome, have proved to be one of the best molecular markers for genetic diversity analysis. International Society for Animal Genetics (ISAG) and FAO advisory group proposed specific microsatellite panels for diversity analysis in livestock species. Microsatellites can be combined with PCR and made more economical, if multiplexing is done along with the usage of fluorescent labelled primers. Usually, 15-25 microsatellites are chosen and data obtained from 30 unrelated individuals from each population. After genotyping, raw data will be obtained in the form of allelic sizes for each microsatellite locus and reliability of data should be checked using appropriate softwares. Genetic variation in the populations can further be assessed by measuring allelic richness, Polymorphic Information Content and private alleles. F-Statistics which describes the statistically expected level of heterozygosity in a population can also be measured from microsatellite data. Genetic distance estimated indicates a measure of genetic divergence between species or between populations within a species and dendrogram can be constructed further. Structure Analysis which detects underlying genetic populations among a set of individuals and Bottleneck analysis which detects genetic signatures of a recent reduction in population size, augments the data on genetic diversity. Though whole genome genotyping arrays with SNP data have advantages, microsatellites are still considered suitable markers to provide complementary information on genetic diversity.