Chikuni K, Mori Y, Tabata T, Saito M, Monma M, Kosugiyama M
National Institute of Animal Industry, Ibaraki, Japan.
J Mol Evol. 1995 Dec;41(6):859-66. doi: 10.1007/BF00173165.
Nucleotide sequences for the kappa-casein precursor proteins have been determined from the genomic DNAs or hair roots of the Ruminantia. The coding regions, exons 2, 3, and 4, were amplified separately via the three kinds of PCRs and then directly sequenced. The primers were designed from the sequence of bovine kappa-casein gene; they were applicable for the amplification of the kappa-casein genes from the 13 species in the Ruminantia except exon 2 of the lesser mouse deer. These results permitted an easy phylogenetic analysis based on the sequences of an autosomal gene. A phylogenetic tree was constructed from the mature kappa-casein sequences and compared with the tree of the cytochrome b genes which were sequenced from the same individuals. The Cervidae (sika deer, Cervus nippon) were separated from the branch of the Bovidae on the tree of kappa-casein genes with a relatively high confidence level of the bootstrap analysis, but included in the branch of the Bovidae on the tree of cytochrome b genes. The kappa-casein tree indicated a monophyly of the subfamily Caprinae, although the internal branches were uncertain in the Caprinae. The tree based on the nucleotide sequences of cytochrome b genes clearly showed the relationships of the closely related species in the genus Capricornis consisting of serow (C. smatorensis), Japanese serow (C. crispus), and Formosan serow (C. swinhoei). These results would be explained by the difference of resolving power between the kappa-casein and the cytochrome b sequences.
已从反刍动物的基因组DNA或发根中确定了κ-酪蛋白前体蛋白的核苷酸序列。编码区，即外显子2、3和4，通过三种PCR分别扩增，然后直接测序。引物是根据牛κ-酪蛋白基因的序列设计的；它们适用于从反刍动物的13个物种中扩增κ-酪蛋白基因，但不包括小鼷鹿的外显子2。这些结果使得基于常染色体基因序列的系统发育分析变得容易。根据成熟的κ-酪蛋白序列构建了系统发育树，并与从相同个体测序的细胞色素b基因的树进行了比较。在κ-酪蛋白基因的树上，鹿科（梅花鹿，Cervus nippon）以相对较高的自展分析置信水平从牛科的分支中分离出来，但在细胞色素b基因的树上包含在牛科的分支中。κ-酪蛋白树表明山羊亚科是单系的，尽管山羊亚科的内部分支不确定。基于细胞色素b基因核苷酸序列的树清楚地显示了由鬣羚（C. smatorensis）、日本鬣羚（C. crispus）和台湾鬣羚（C. swinhoei）组成的鬣羚属中密切相关物种的关系。这些结果可以用κ-酪蛋白和细胞色素b序列之间分辨能力的差异来解释。
