Figure 3.

Phylogenetic analysis of class II α chain genes. Cafa, Canis familiaris (dog); Hosa, Homo sapiens (human); Bota, Bos taurus (bovine); Rano, Rattus norvegicus (rat); Maru, Macropus rufogriseus (red-necked wallaby); Modo, Monodelphis domestica (opossum); Orcu, Oryctolagus cuniculus (rabbit); Eqca, Equus caballus (horse); Cacr, Caiman crocodilus (spectacled caiman); Gaga, Gallus gallus (chicken); Oran, Ornithorhynchus anatinus (platypus); Xela, Xenopus laevis (African clawed frog). The abbreviations used to describe taxonomic affiliation of each species in the tree are outlined in Figure 4a. A black diamond highlights platypus DRA. Tree construction using the NJ method is outlined in Materials and methods. Numbers indicate bootstrap support in percent. Branch lengths are proportional to number of substitutions. The scale bar indicates 20% substitutions per site. Sequences used and their accession numbers are listed in Additional data file 10.