Identification of the KAP27-1 gene in sheep and its effect on wool traits

Abstract

The keratin-associated proteins (KAPs) are structural components of wool and hair fibres, with over 90 genes that encode these proteins having been identified in mammalian species. A KAP gene called KRTAP27-1 was recently identified in goats, but the gene has not been reported in the closely related ruminant species sheep. In this study, we used a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis to find ovine KRTAP27-1 and investigate nucleotide sequence variation in the gene. Our analysis revealed four sequence variants (named A to D) in 399 New Zealand Merino × Southdown-cross sheep. Within these sequence variants there were five single nucleotide polymorphisms (SNPs) in the coding region, including two non-synonymous SNPs. Six genotypes (AA, AB, AC, BB, BC and BD) of KRTAP27-1 were detected, and for the three genotypes with a frequency of over 5.0%, sheep of genotypes AB and BB produced wool of higher mean staple length (MSL) and higher greasy fleece weight (GFW) than sheep of genotype AA. These results suggest that variation in ovine KRTAP27-1 may be affecting wool growth and thus production.