Mariani P, Moller M J, Høyheim B, Marklund L, Davies W, Ellegren H, Andersson L
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
J Hered. 1996 Jul-Aug;87(4):272-6. doi: 10.1093/oxfordjournals.jhered.a023000.
A linkage map of pig chromosome 6 was constructed using a wild pig/Large White intercross pedigree. The map comprises 23 polymorphic loci, and the sex-average map length is approximately 170 cM. The study adds three new genes to the chromosome 6 map: the extension (E) coat color locus, and the blood group O (EAO) and tyrosine aminotransferase (TAT) loci. Segregation at the E locus determined two coat color phenotypes among the F2 animals: wild-type color (El-) and black-spotting (Ep/Ep). The E locus showed close genetic linkage to the most distal marker (S0035) on the short arm of chromosome 6. Comparative coat color genetics as well as comparative mapping strongly suggest that E in pigs encodes the melanocyte-stimulating hormone receptor, as previously shown for the corresponding coat color loci in mouse and cattle. TAT was also mapped to the distal part of 6p, whereas EAO was the most distal marker on 6q. A clear tendency for a higher recombination rate in both terminal regions was observed. A model for the evolution of pig chromosome 6, based on comparative mapping data, is presented.
利用野猪/大白猪杂交系谱构建了猪6号染色体的连锁图谱。该图谱包含23个多态性位点，性别平均图谱长度约为170厘摩。该研究为6号染色体图谱增加了三个新基因：扩展（E）毛色位点、血型O（EAO）和酪氨酸转氨酶（TAT）位点。E位点的分离在F2动物中确定了两种毛色表型：野生型毛色（El-）和黑斑（Ep/Ep）。E位点与6号染色体短臂上最远端的标记（S0035）显示出紧密的遗传连锁。比较毛色遗传学以及比较图谱强烈表明，猪中的E编码促黑素细胞激素受体，正如之前在小鼠和牛中相应的毛色位点所显示的那样。TAT也被定位到6p的远端部分，而EAO是6q上最远端的标记。在两个末端区域均观察到明显的较高重组率趋势。基于比较图谱数据，提出了猪6号染色体的进化模型。
