家鹅品种细胞色素b基因序列分析及其系统发育关系

测定了15个中国家鹅和2个欧洲家鹅品种44个个体线粒体细胞色素b基因全序列（1143 bp），并结合GenBank中的野生种白额雁序列比较分析表明，检测到31个可变位点和4种单倍型，没有发现缺失或插入，核苷酸多样度和单倍型多样度分别为0.00648和0.45，密码子第三位点G碱基的含量较低（14.2%），A、T和C的含量极相似，第一、二位点的偏倚度（0.057和0.223）低于第三位点（0.492），转换数明显高于颠换数(Ts/Tv＝9.5～19)，密码子第三位点的转换数最高。系统发育分析结果支持中国家鹅的两个不同起源学说。

Phylogenetic Relationships among Domestic Goose Breeds Based on Mitochondrial Cytochrome B Gene Sequence Variation

The mitochondrial cytochrome b (cyt b) gene of 17 breeds of domestic goose (2 in Europe and 15 in China) was sequenced and compared with that of the representative of wild species Anser albifrons. Sequence analysis revealed that thirty-one variable sites and 4 different haplotypes were found among the 45 sequences examined, and nucleotide diversity and haplotype diversity were 0.0068 and 0.45, respectively. Mutations of insertion/deletion were not found. Across all sites,the abundance of G was low (14.2%), whereas the percentages of A, T, and C were quite similar among three Anser goose species. The frequency of guanine differs greatly among the three codon positions. Compositional bias is smaller at first and second positions (0.057 and 0.223) than at third positions (0.492), the probability of transition was higher than that of tranversion (Ts/Tv=9.5-19), there was the highest number of transition in the third codon. The phylogenetic analysis support the hypothesis of dual origin of domestic geese.