Association of wool traits with variation in the ovine KAP1-2 gene in Merino cross lambs

The impact of variation in KRTAP1-2 on wool traits was investigated in 383 Merino cross sheep, sired by six different rams. DNA samples from these sheep were genotyped at KRTAP1-2 using PCR-single strand conformational polymorphism (PCR-SSCP) analysis. Seven previously reported gene variants (A–C, E–H) and two newly identified variants (J and K) were detected, with a frequency of 25.5%, 10.3%, 1.4%, 0.1%, 39.4%, 12.8%, 9.1%, 0.4% and 0.3%, respectively. The effects of variants E, J and K on wool traits were not investigated as they were found at a very low frequency. Of the other six variants; A, B and C were found to be associated with a number of wool traits, but the strongest association was with three correlated traits clean fleece weight (CFW), greasy fleece weight (GFW) and yield. The presence of A was associated with an increase in GFW, CFW and yield. The presence of B was also associated with an increase in GFW, CFW and yield. The presence of C was associated with a decrease in GFW and CFW, but increased yield. Genotypes AF and AG had a higher GFW than FG and FH; AF and AG had a higher CFW than FG; and sheep of AF, AG and BF had a higher yield than those of FF and FG. These results suggest that consideration of ovine KRTAP1-2 may be useful when developing breeding programs based on wool weight.