Relationships of IGFBP-3 gene polymorphism with cashmere traits in raini cashmere goat

Insulin-like growth factor binding protein-3 (IGFBP-3) gene is a structural gene responsible for the multiple influences of insulin like growth factors (IGFs) system. This study was carried out to determine the genetic diversity of Raeini Cashmere goat and its relationship with cashmere production, using two markers, HaeIII and XspI PCR-RFLPs for goat IGFBP-3 locus. A number of whole blood samples were randomly collected from 100 individual goats (males and females). DNA extraction from whole blood samples were done using modified salting out method. In the PCR-RFLP analysis with HaeIII, the frequencies of H1 and H2 alleles were 0.8 and 0.2 respectively and the frequencies of X1 and X2 alleles were 0.34 and 0.66 respectively. Shannon and Nei indices, observed and expected heterozygosities were 0.50, 0.32, 0.22 and 0.32 for HaeIII RFLP respectively and 0.64, 0.44, 0.24 and 0.45 for XspI RFLP respectively. The individuals with genotype H1H1 had higher cashmere yield than that of genotype H2H2 in three-year-old (P<0.05), but trend was reversed in five-year-old (P<0.05). But, XspI locus did not show significant effect. It could be concluded that Raeini Cashmere goat has high genetic diversity and the IGFBP-3 gene could be exploited as a candidate gene for marker-assisted selection in this breed.