Abstract :
The keratins and keratin-associated proteins (KAPs) are a large heterogeneous group of
proteins that make up about 90% of the cashmere fiber. Keratin-associated proteins 9.2
gene (KAP9.2) is one of the ultra high sulfur KAPs, which might play an important role in
the bundling of intermediate filaments. In this study, the deletion/insertion mutation of
KAP9.2 gene in 997 cashmere goat samples was firstly detected, at the same time, parts
of these samples were sequenced. The results showed that two alleles were detected at
this KAP9.2P1 locus, named alleleWand D. The frequencies of the KAP9.2-Wallele in Inner
Mongolia White cashmere (n = 785) and Shaanbei White cashmere goat breeds (n=212)
were 0.878 and 0.790, respectively. The 2-test showed that the genotype distributions in
these two cashmere goat breedswere not in agreement with Hardy–Weinberg equilibrium.
According to the classification of polymorphism information content (PIC), Shaanbei White
cashmere goat was more polymorphic at this locus. Moreover a 30 bp-deletion mutation
was described at KAP9.2P2 locus for the first time and no deletion/insertionwas described at
KAP9.2P1 locus. The results possibly revealed that the size polymorphism existed in the two
Chinese cashmere goat and the 30 bp-deletion mutation was possibly caused by variations
in the number of the decapeptide repeat structures.
