Berryere Tom G, Kerns Julie A, Barsh Gregory S, Schmutz Sheila M
Department of Animal and Poultry Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, Canada S7N 5A8.
Mamm Genome. 2005 Apr;16(4):262-72. doi: 10.1007/s00335-004-2445-6.
The type of pigment synthesized in mammalian hair, yellow-red pheomelanin or black-brown eumelanin, depends on the interaction between Agouti protein and the Melanocortin 1 receptor. Although the genetics of pigmentation is broadly conserved across most mammalian species, pigment type-switching in domestic dogs is unusual because a yellow-tan coat with variable amounts of dark hair is thought to be caused by an allele of the Agouti locus referred to as fawn or sable (a(y)). In a large survey covering thirty seven breeds, we identified an Agouti allele with two missense alterations, A82S and R83H, which was present (heterozygous or homozygous) in 41 dogs (22 breeds) with a fawn or sable coat, but was absent from 16 dogs (8 breeds) with a black-and-tan or tricolor phenotype. In an additional 33 dogs (14 breeds) with a eumelanic coat, 8 (German Shepherd Dogs, Groenendaels, Schipperkes, or Shetland Sheepdogs) were homozygous for a previously reported mutation, non-agouti R96C; the remainder are likely to have carried dominant black, which is independent of and epistatic to Agouti. This work resolves some of the complexity in dog coat color genetics and provides diagnostic opportunities and practical guidelines for breeders.
哺乳动物毛发中合成的色素类型，即黄红色的褐黑素或黑褐色的真黑素，取决于刺豚鼠蛋白与促黑素皮质素1受体之间的相互作用。尽管色素沉着的遗传学在大多数哺乳动物物种中广泛保守，但家犬的色素类型转换却不寻常，因为带有不同数量深色毛发的黄棕色被毛被认为是由刺豚鼠基因座的一个等位基因引起的，该等位基因被称为小鹿色或貂皮色（a(y)）。在一项涵盖37个品种的大型调查中，我们鉴定出一个具有两个错义改变A82S和R83H的刺豚鼠等位基因，该等位基因在41只（22个品种）具有小鹿色或貂皮色被毛的犬中存在（杂合或纯合），但在16只（8个品种）具有黑褐色或三色表型的犬中不存在。在另外33只（14个品种）具有真黑素被毛的犬中，8只（德国牧羊犬、比利时牧羊犬、舒柏奇犬或设得兰牧羊犬）对先前报道的突变非刺豚鼠R96C是纯合的；其余的可能携带显性黑色基因，该基因独立于刺豚鼠基因且对其具有上位性。这项工作解决了犬被毛颜色遗传学中的一些复杂性问题，并为育种者提供了诊断机会和实用指南。
