Adalsteinsson S, Bjarnadottir S, Vage D I, Jonmundsson J V
Nordic Gene Bank for Farm Animals, Department of Animal Science, Agricultural University of Norway, Aas.
J Hered. 1995 Sep-Oct;86(5):395-8. doi: 10.1093/oxfordjournals.jhered.a111609.
Inheritance of the colors black, brown, and red in Icelandic cattle was studied. The three colors are produced by two loci, Extension (E) and Agouti (A), with three alleles at the E locus: E(d) for dominant black; E+, intermediate, which allows expression of A locus alleles; and e for recessive red color. Two alleles are postulated at the A locus: A+, producing brown, and a, producing recessive black (nonagouti) when homozygous in E+/- animals. The dominant and recessive types of black are indistinguishable from each other phenotypically. The A alleles are only able to express their effect in E+/- genotypes. The E and A loci in cattle are postulated to be homologous to the E and A loci in the mouse.
对冰岛牛黑色、棕色和红色的遗传进行了研究。这三种颜色由两个基因座产生，即扩展基因座（E）和刺鼠基因座（A），E基因座有三个等位基因：E(d) 代表显性黑色；E+，为中间型，可使A基因座等位基因得以表达；e代表隐性红色。假定A基因座有两个等位基因：A+，产生棕色，而a在E+/-动物中纯合时产生隐性黑色（非刺鼠色）。显性和隐性类型的黑色在表型上无法相互区分。A等位基因仅能在E+/-基因型中发挥作用。牛的E和A基因座被假定与小鼠的E和A基因座同源。
