Identification of the keratin-associated protein 13-3 (KAP13-3) gene in sheep

The study identified the KAP13-3 gene in 147 New Zealand Romney cross-bred sheep, revealing it as an intronless gene encoding a cysteine-rich polypeptide with high serine and threonine content, which could be phosphorylated to influence keratin assembly and wool traits. Five different alleles (A-E) were observed with varying frequencies. The ovine KAP13-3 gene showed greater similarity to the bovine KRTAP13-3 than to human sequences, indicating evolutionary divergence after the sheep-cattle split but before primates. The research suggested that amino acid substitutions could impact protein charge and phosphorylation, thereby affecting wool quality.