Imes D L, Geary L A, Grahn R A, Lyons L A
Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis 95616, USA.
Anim Genet. 2006 Apr;37(2):175-8. doi: 10.1111/j.1365-2052.2005.01409.x.
Albino phenotypes are documented in a variety of species including the domestic cat. As albino phenotypes in other species are associated with tyrosinase (TYR) mutations, TYR was proposed as a candidate gene for albinism in cats. An Oriental and Colourpoint Shorthair cat pedigree segregating for albinism was analysed for association with TYR by linkage and sequence analyses. Microsatellite FCA931, which is closely linked to TYR and TYR sequence variants were tested for segregation with the albinism phenotype. Sequence analysis of genomic DNA from wild-type and albino cats identified a cytosine deletion in TYR at position 975 in exon 2, which causes a frame shift resulting in a premature stop codon nine residues downstream from the mutation. The deletion mutation in TYR and an allele of FCA931 segregated concordantly with the albino phenotype. Taken together, our results suggest that the TYR gene corresponds to the colour locus in cats and its alleles, from dominant to recessive, are as follows: C (full colour) > c(b) (burmese) > or = c(s) (siamese) > c (albino).
白化病表型在包括家猫在内的多种物种中都有记录。由于其他物种的白化病表型与酪氨酸酶(TYR)突变有关,因此有人提出TYR是猫白化病的候选基因。通过连锁分析和序列分析,对一个白化病性状分离的东方短毛猫和重点色短毛猫家系进行了与TYR的关联分析。对与TYR紧密连锁的微卫星FCA931以及TYR序列变异进行了白化病表型分离测试。对野生型和白化病猫的基因组DNA进行序列分析,发现在第2外显子975位的TYR中有一个胞嘧啶缺失,这导致了移码突变,在突变下游9个残基处产生了一个提前终止密码子。TYR中的缺失突变和FCA931的一个等位基因与白化病表型一致分离。综上所述,我们的结果表明,TYR基因与猫的毛色位点相对应,其等位基因从显性到隐性依次为:C(全色)>c(b)(缅甸猫色)>或=c(s)(暹罗猫色)>c(白化病)。