Aravindakshan, T VAmrita Susan, JacobKAU2019-06-072019-06-072005172406http://krishikosh.egranth.ac.in/handle/1/5810107704PGThe study was undertaken to assess the genetic variability among four goat breeds of South India using microsatellite markers. Three breeds studied were native to Kerala. These were Malabari, Attappadi Black and non-descript goats of Thrissur. The fourth breed, Salem Black, originated in the Salem district of Tamil Nadu. Microsatellite analysis was carried out using four highly polymorphic bovine markers. Blood samples from 30 genetically unrelated animals of each breed were collected and used as a source of DNA. The phenol-chloroform extraction procedure was used and the mean yield of DNA obtained was 361.43±10.73 µg/five ml blood. The four markers selected for the study were, INRA63, ILSTS030, HUJII77 and BM6121. PCR conditions were standardised for all the primers. The forward primer of each primer pair used in the PCR assay was end labeled with γ32P-ATP prior to setting up of the PCR. M13 DNA was sequenced and used as the size standard. The PCR products were separated by denaturing polyacrylamide gel electrophoresis. Detection of the products was done by autoradiography. Gels after electrophoresis were dried and was set for autoradiography with X-ray film in a cassette fitted with intensifying screen. Allele sizes were obtained by comparing with the sequence of M13 single stranded DNA size standard. A total of eleven alleles were detected at the INRA63 locus. The mean heterozygosity and PIC values obtained were 0.774 and 0.743, respectively. Seventeen alleles were detected at the ILSTS30 locus. The mean values of heterozygosity and PIC were 0.878 and 0.866, respectively. Thirteen alleles were detected at the BM6121 locus with mean heterozygosity and PIC values of 0.851 and 0.833, respectively. The HUJII77 locus was the most polymorphic of all the four loci detecting 21 alleles. The mean heterozygosity and PIC values were 0.899 and 0.88, respectively. The allele frequency measures were used to estimate the Nei’s standard genetic distance among the populations using the PHYLIP package. The distance measures ranged from 0.388 to 0.224, with the highest value noticed between Salem Black and non-descript goats of Thrissur and the lowest between Malabari and non-descript animals. A dendrogram was constructed using the POPGENE program which grouped the Salem Black and Attappadi Black goats in one cluster and Malabari and the non-descript goats of Thrissur in another.ennullThesis