Genetic Polymorphism and Association of KAP16.6 Gene with Pashmina Fiber Traits in Changthangi Goats

Pashmina is the fine undercoat of the Changthangi goats (Capra hircus) with Keratin-associated proteins (KAPs) as one of its main structural components. KAPs form a semi-rigid matrix in which the Keratin intermediate filaments (KIFs) are embedded. In the present study, an attempt was made to elucidate the polymorphism of KAP16.6 gene loci and its association with fiber yield and quality traits (fine yield, mean fiber diameter, mean fiber length, and guard hair percentage). A total of 103 animals of Changthangi goats were randomly selected and genomic DNA was isolated from blood samples. After amplification of the coding region of KAP16.6 (254 bp) gene, restriction digestion with HindIII enzyme (AAG/CTT) produced two polymorphic patterns in the Changthangi goats. The genotypic distribution of the designated genotypes A1A1 (0.0), A2A2 (0.379), and A1A2 (0.621) of KAP16.6 gene varied significantly (p < .01) from Hardy-Weinberg equilibrium. Missense mutation AGC (Serine) > AAC (Asparagine) was identified at KAP16.6 locus in Changthangi goats for the first time. The genetic variability parameters for the gene loci analyzed were: heterozygosity value 0.4283, PIC: 0.3366, effective allele no 1.7492 and Shannon index (I) of 0.6196. The estimated PIC value reflected median polymorphism exhibited by the Changthangi goat population under study for the selected gene. Statistical analysis further revealed a significant effect of KAP16.6 genotype on the fiber length (p < .05) whereas the effect was nonsignificant for other Pashmina production traits under study. The results from the present study have practical significance in the breeding plans for Changthangi goats in this region for improved production performance.