Comparison of MHC genes among distantly related members of the genus Mus.

The genomic content of class I and class II MHC DNA sequences in a variety of wild mice has been analyzed. The panel of mice includes members of three subgenera of the genus Mus. By genomic hybridization with the use of a variety of DNA probes, both class I and class II DNA sequences appear to be conserved in all of the species examined. However, the number of class I DNA sequences differs among the species. Furthermore, this variation appears to result from differential increases within subsets of class I genes. These data suggest that the class I multigene family is dynamic and changing over short periods of evolutionary time. In contrast, none of the class II genes appears to vary in copy number. More extensive polymorphism was noted amongst the class II beta genes than the alpha genes. Interestingly, the genomic sequence corresponding to E beta 2 is highly conserved, leading to the prediction that it is a genetically functional sequence.