Figure 1.

Comparative map of the mammalian MHC region. (a) Aligned MHC regions of human, rat, opossum [4,5,10] and the sequenced portions of the platypus MHC. Intervals are color-coded: class I regions are shown in red; class II regions in blue; and framework regions including class III in yellow. Circled numbers denote framework genes that typically flank these intervals: 1, Col11a2; 2, Btnl2; 3, Bat1/Mccd1; 4, Pou5f1; 5, Gnl1; 6, Flj22638; 7, Trim39; 8, Trim26; 9, Tctex4; 10, Mog. Dotted lines link orthologous positions defined by genes 1-10 in the four species. Tctex4 is missing from the MHC of opossum. Question marks indicate that the borders of the class I/II region in platypus have not been cloned. Rat has three additional RT1-M gene blocks outside the interval shown. (b) Comparison of the class II region of rat and human, and the opossum class I/II region to platypus based on annotation of platypus BAC 462c1. Genes are color-coded: framework genes are shown in green; class I genes in red; class II α chains in light blue; and class II β chains in dark blue (for phylogenetic relations among class II genes, see Additional data file 2). Non-class I and non-class II genes or pseudogenes unique for a given species are displayed in grey. Hatching between BTNL2 and BTNL5 in opossum and between DRB1 and DRB9 in the HLA indicates that further BTNL or DRB genes are located within these intervals. Orthologous genes are linked by colored bars. (c) Detailed map of the Bat4 to Cdsn interval, including a class I gene block.