IGF-1 Gene Polymorphism and its Association with Cashmere Fiber Trait in Changthangi Goats

Abstract

ABSTRACT The Cashmere (Pashmina) fiber attracts great demand worldwide for its fineness. To identify and determine the role of Insulin-like Growth Factor-1 (IGF-1) gene polymorphism on Pashmina fiber traits (quality and quantity), exon IV, and part of intron IV of the IGF-1 gene of Changthangi goats were analyzed. 103 Changthangi goats of either sex were divided into two groups, the high producers and low producers of Pashmina. Upon restriction digestion with HaeIII, three genotypes were identified, i.e., A1A1 (0.253), A2A2 (0.320), and A1A2 (0.427). These genotypes did not vary significantly (p > .05) from Hardy–Weinberg Equilibrium. DNA sequence analysis revealed G > C transversion in intron-IV of IGF-1 gene at the HaeIII restriction site. The SNP effect of two alleles on mean Cashmere fiber diameter of down fibers (MFD) was statistically significant (p < .05) and the average finest fiber diameter was 13.46 µ for genotype A2A2. The mean genetic variability parameters for the gene analyzed were heterozygosity value (0.4977), PIC Value (0.3738), Effective allele no (1.9908),and Shannon index I (0.6908). The significant association of IGF-1 gene polymorphism and fiber finesse can be exploited in breeding programmes to improve the production and quality of Pashmina fiber in goat populations.