Mhc class I and non-class I gene organization in the proximal H2-M region of the mouse

A bacterial artificial chromosome (BAC) contig was constructed across the p roximal part of the H2-M region from the major histocompatibility complex ( Mhc) of mouse strain 129 (H2(bc)). The contig is composed of 28 clones that span approximately 1 megabasepair (Mb), from H2-T1 to Mog, and contains three H2-T genes and 18 H2-M genes. W e report the fine mapping of the H2-M class I gene cluster, which includes the previously reported M4-M6, the M1 family, the M10 family, and four addi tional class I genes. All but two of the H2-M class I genes are conserved a mong haplotypes H2(k), H2(b), and H2(bc), and only two genes are found in p olymorphic HindIII fragments. Six evolutionarily conserved non-class I gene s were mapped to a 180 kilobase interval in the distal part of the class I region in mouse, and their order Znf173-Rfb30-Tctex5-Tctex6-Tctex4-Mog was found conserved between human and mouse. In this Znf173-Mog interval, three mouse class I genes, M6, M4, and M5, which are conserved among haplotypes, occupy the same map position as the human HLA-A class I cluster, which var ies among haplotypes and is diverged in sequence from the mouse genes. Thes e results further support the view that class I gene diverge and evolve ind ependently between species.