[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.