Figure 4.

Phylogenetic tree of MHC class I genes from various vertebrate species. This tree was constructed by using p-distances (39) for the amino acid sequences (274 residues) for domains α₁, α₂, and α₃. Class Ib genes are denoted by (b) except for Xenopus genes NC4, NC7, and NC8. Other genes are primarily class Ia genes. Asterisks indicate cDNA data, where the identification of loci or alleles is ambiguous. In this paper we used common species or genus names to designate their MHC genes to make the paper understandable for nonspecialists. The wallaby is a marsupial species; Xenopus is Xenopus laevis.