Study on KAP 8.2 Gene Polymorphisms in Nagaland Long Haired Goat of Northeastern India

Abstract

The study was conducted to detect polymorphism of keratin associated protein 8.2 (KAP 8.2) gene to determine association between the genotype and fibre traits in Nagaland Long Haired goats (NLHG) of Northeastern India. NLGH is an important germplasm which comprises a small population of non-descript indigenous animals having unique long fibres over the body. The fibre traits studied were fibre diameter, fibre yield and fibre length. Twenty five animals were used to detect polymorphisms in hircine KAP 8.2 gene by means of Polymerase chain reaction–restriction length polymorphism (PCR-RFLP). Digestion of the PCR product using Pvu II revealed two genotypes viz. AA and AB.  AA genotype yielded one fragment (501bp) and AB genotype yielded two fragments (331 and 170 bp). Allele A and genotype AB were predominant in the breed. The χ² test revealed that the genotype frequencies were not in agreement with Hardy-Weinberg equilibrium in the population . The frequencies of A and B alleles were found to be 0.700 and 0.300 respectively and the genotypic frequencies of KAP 8.2 were found to be 0.400 and 0.600 for AA and AB genotypes respectively.  Fibre diameter of NLHG was found to differ significantly (P < 0.05) according to the genotypes. Goats with AA genotypes had significantly thinner fibre diameter (0.214 ± 0.006 mm) as compared to that of AB genotypes (0.257 ± 0.007 mm). However, fibre yield and fibre length did not differ in respect of the two genotypes. By further analysis, at position 124 bp and 281 bp of the original sequence of KAP 8.2 gene T       C and G        C nucleotide substitution was found. Presence of polymorphism in KAP 8.2 opens interesting prospects for future selective breeding programme, especially based on marker-assisted selection.