Effect of the polymorphisms of keratin associated protein 8.2 gene on fibre traits in Inner Mongolia cashmere goats

The aim of the experiment was to detect polymorphisms in the keratin-associated protein 8.2 (KAP8.2) gene to determine associations between the genotype and fibre traits in Chinese Inner Mongolia cashmere goats. The fibre traits data investigated were cashmere fibre diameter, combed cashmere weight, cashmere fibre length and guard hair length. Five hundred and forty-two animals were used to detect polymorphisms in the complete coding sequence of the hircine KAP8.2 gene by means of PCR-SSCP. The results identified six genotypes, AA, BB, DD, AB, AD and BD, coded for by three different alleles A, B and D. Two SNPs in the coding region were confirmed by sequencing, which were A214G and T218C respectively. The relationships between the genotypes and cashmere fibre diameter, combed cashmere weight, cashmere fibre length and guard hair length were analyzed. There were significant differences (p < 0.01) between the associations of the different genotypes with cashmere fibre diameter, cashmere weight and hair length. Cashmere length was the only trait that was not associated with the genotypes. The genotype AA (0.73) was found to be predominant in Inner Mongolia cashmere goats and the animals with this genotype had the thinnest cashmere fibre diameter compared with the other genotypes. These results suggested that polymorphisms in the hircine KAP8.2 gene may be a potential molecular marker for cashmere fibre diameter in cashmere goats.