Linkage relationships between keratin-associated protein (KRTAP) genes and growth hormone in sheep.

The ovine hair keratin-associated protein (KRTAP) genes are grouped into several families. In this study, we analyzed linkage relationships between members of four KRTAP families and growth hormone and beta-hemoglobin. Restriction fragment length polymorphisms and a microsatellite polymorphism were typed in 10 sire groups from a flock of Australian Merino sheep. Two linkages, both previously undetected in sheep or any other mammal, were found. They were between growth hormone (GH) and the high-sulfur keratin gene family KRTAP1 (previously called high-sulfur B2C) at theta = 0.10, Z = 3.01 and between two high-glycine-tyrosine class genes, KRTAP6 (previously high-glycine-tyrosine type II) and KRTAP8 (previously high-glycine-tyrosine type I-F), at theta = 0.15, Z = 5.0. The high level of conservation of the mammalian genome at these recombination values suggests that these linkages might be found in distantly related mammalian species.