Figure 3. Phylogenetic relationship and VISTA plot of the MHC class II nucleotide sequences from eight mammal species: human (Homo sapiens), cattle (Bos taurus), sheep (Ovis aries), pig (Sus scrofa), horse (Equus caballus), dog (Canis familiaris), cat (Felis catus) and Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis).

The corresponding MHC class II regions are labeled HLA, BoLA, OLA, SLA, ELA, DLA, FLA and Neas, respectively. For the sake of comparative sequence analysis, the orientations of the MHC class IIb regions from Yangtze finless porpoise, cattle and sheep were inverted. The height of the bars represents the repeats distributing in Neas. Different color bar represents different kind of repeat as that showed on Fig. 1.