The arrangement of H-2 class I genes in mouse t haplotypes.

The t haplotypes of mouse chromosome 17 bear a number of interesting mutations and rearrangements, some of which map close to the H-2 complex. Since there are many H-2 class I genes of unknown function, we have investigated their arrangement in t haplotypes using genomic Southern blots. We present a detailed chart of the H-2w30 (tw12) complex, and compare it with the arrangement in other t haplotypes and standard mouse haplotypes. The chart shows duplications, deletions, and reshuffling of conserved and divergent regions. The two major features of the t arrangement--large deletions in the Qa and Tla regions--have analogues in some standard strains, so it is unlikely that these deletions are responsible for t-specific phenotypes. The differences between t and standard mouse strains are similar, in nature and in degree, to those between different standard strains.