Sixteen new H-2 haplotypes derived from wild mice.

Wild mice captured in Texas, Scotland, Federal Republic of Germany, Denmark, Spain, Greece, Israel, Egypt, and Chile were mated to inbred strains and through successive backcross matings and H-2 typing lines homozygous for wild-derived H-2, haplotypes were established. The lines, which are neither congenic nor inbred, were then typed with antibodies defining known H-2 alleles at class I and class II loci. In addition, antisera were produced by the immunization of inbred strains with tissues of the new lines. Sixteen of the lines were characterized in this manner. The characterization resulted in the identification of 16 new H-2 haplotypes, 11 new K alleles, 10 new D alleles, and 21 new class I antigenic determinants, most of them of the private type. Most of the haplotypes represent natural recombinants sharing segments of the H-2 complex with previously identified haplotypes. A number of haplotypes are recombinants between the K and the A loci, which in genetic studies have proved difficult to separate. The lines, however, also provide evidence for preservation of blocks of genes in the H-2 complex, particularly in the class II region. Some of class I alleles previously found in wild mice from Michigan have now been found again in these mice. Several class II alleles of these lines appear to be the same as those found in inbred strains. Identical or nearly identical class I and class II alleles thus commonly occur in different populations. These findings strengthen the argument that in populations, H-2 alleles are relatively stable.