Identification of the Ovine Keratin-Associated Protein 22-1 (KAP22-1) Gene and Its Effect on Wool Traits

In the 2017 study, researchers identified the ovine homolog of the human KAP22-1 gene, which is a keratin-associated protein (KAP) important for wool and hair fiber structure. Using PCR-SSCP analysis, they detected three different nucleotide sequences (A-C) representing genetic variation in the KRTAP22-1 gene among 390 Merino × Southdown-cross lambs and 75 New Zealand Romney sheep. Two single nucleotide polymorphisms (SNPs) were identified. The most common variant in NZ Romney sheep was B (81.3%), while variant A was more common in the Merino × Southdown-cross lambs (51.8%). The study found that the presence of variant B was associated with increased wool yield and decreased mean fiber curvature. Sheep with genotype BB or AB had higher wool yields compared to those with genotype AA, indicating that KRTAP22-1 variation could be significant for breeding programs aimed at improving wool yield or modifying wool curvature.