Analysis of the keratin associated protein gene KRTAP6-1 in New Zealand Wiltshire sheep

Keratin associated proteins (KAPs) and keratins (Ks) are key elements in the structure of wool fibre and determine the phenotypes seen in sheep. The abundance of the KAP gene family (KRTAP-n) varies in wool fibre. Variation within the ovine KAP gene KRTAP6-1 was screened for using PCR-SSCP analysis. One hundred and eight New Zealand Wiltshire sheep from a North Canterbury stud were sampled for DNA, and additional to five previously reported variants of KRTAP6-1, A – E, two new variants, F and G, were found. The sampled Wiltshire sheep had five KRTAP6-1 gene variants, A, B, D, F and G, but variants C and E were not found. Of the five gene variants identified, B was the most common at a frequency of 56%, followed by the new variants F and G at 16% and 12% respectively. A and D had frequencies of 11% and 4% respectively. The KRTAP-n genes coding for wool fibre traits are multi-genic and highly polymorphic making selective breeding for desirable traits difficult. By gaining a better understanding of the genes involved in wool fibre properties more consistent fibre production may be achieved. Improved knowledge may offer us clues as to what underpins the fundamental differences between Wiltshire sheep and other breeds