Figure 4.

Phylogenetic tree of the MHC class II genes of fourteen mammalian species. (A) Phylogenetic tree of MHC class II A genes. (B) Phylogenetic tree of MHC class II B genes. These phylogenetic trees were constructed using the maximum likelihood method, based on the Kimura 2-parameter model. One thousand bootstrap replications were performed, and the percentages larger than 50 are shown next to the branches. The MHC class II genes of mammalian species are indicated by the combination of abbreviated Latin animal names and gene names. DO, DR, DY, and DQ genes are indicated by red, green, orange, and purple, respectively. The topology of the phylogenetic tree based on the maximum likelihood method and the neighbor-joining method was the same, but only the maximum likelihood tree is shown here.