Unit of Animal Genomics, GIGA-R & Faculty of Veterinary Medicine, University of Liège, 4000-Liège (Sart Tilman), Belgium.
Nature. 2012 Feb 1;482(7383):81-4. doi: 10.1038/nature10757.
Colour sidedness is a dominantly inherited phenotype of cattle characterized by the polarization of pigmented sectors on the flanks, snout and ear tips. It is also referred to as 'lineback' or 'witrik' (which means white back), as colour-sided animals typically display a white band along their spine. Colour sidedness is documented at least since the Middle Ages and is presently segregating in several cattle breeds around the globe, including in Belgian blue and brown Swiss. Here we report that colour sidedness is determined by a first allele on chromosome 29 (Cs(29)), which results from the translocation of a 492-kilobase chromosome 6 segment encompassing KIT to chromosome 29, and a second allele on chromosome 6 (Cs(6)), derived from the first by repatriation of fused 575-kilobase chromosome 6 and 29 sequences to the KIT locus. We provide evidence that both translocation events involved circular intermediates. This is the first example, to our knowledge, of a phenotype determined by homologous yet non-syntenic alleles that result from a novel copy-number-variant-generating mechanism.
颜色侧身性是一种牛的显性遗传表型，其特征是在侧腹、鼻子和耳朵尖端的色素区域发生极化。它也被称为“lineback”或“witrik”（意思是白色背部），因为颜色侧身的动物通常在脊柱上有一条白色带。颜色侧身性至少从中世纪就有记载，目前在全球的几个牛品种中分离出来，包括比利时蓝牛和瑞士褐牛。在这里，我们报告说颜色侧身性是由 29 号染色体上的第一个等位基因（Cs(29)）决定的，它是由包含 KIT 的 6 号染色体 492 千碱基片段易位到 29 号染色体引起的，第二个等位基因（Cs(6)）是由第一个等位基因通过融合的 6 号和 29 号染色体 575 千碱基序列归位到 KIT 基因座产生的。我们提供的证据表明，这两个易位事件都涉及环状中间体。这是我们所知的第一个由同源而非同线性等位基因决定的表型的例子，这些等位基因是由一种新的拷贝数变异生成机制产生的。
