Keratin-associated proteins (KAPs) are structural components of wool and hair fibers. To date, eight high glycine/tyrosine KAP (HGT-KAP) families have been identified in humans, but only three have been identified in sheep. In this study, the putative ovine homolog of the human KAP22-1
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Keratin-associated proteins (KAPs) are structural components of wool and hair fibers. To date, eight high glycine/tyrosine KAP (HGT-KAP) families have been identified in humans, but only three have been identified in sheep. In this study, the putative ovine homolog of the human KAP22-1 gene (
KRTAP22-1) was amplified using primers designed based on a human
KRTAP22-1 sequence. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) was used to screen for variation in
KRTAP22-1 in 390 Merino × Southdown-cross lambs and 75 New Zealand (NZ) Romney sheep. Three PCR-SSCP banding patterns were detected and DNA sequencing revealed that the banding patterns represented three different nucleotide sequences (
A–C). Two single nucleotide polymorphisms (SNPs) were identified in these sequences. Variant
B was most common with a frequency of 81.3% in NZ Romney sheep, while in the Merino × Southdown-cross lambs,
A was more common with a frequency of 51.8%. The presence of
B was found to be associated with increased wool yield and decreased mean fiber curvature (MFC). Sheep of genotype
BB or
AB had a higher wool yield than those of genotype
AA. These results suggest that ovine
KRTAP22-1 variation may be useful when developing breeding programs based on increasing wool yield, or decreasing wool curvature.
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