Allele Specific Oligonucleotide Probes for Mouse I-A Region and Gene: I-Aß

MHC Class II gene expression is being intensively studied in vitro. In vivo class II gene expression that occurs during G.V.H.R. and allograft reaction has not been studied as well as the gene expression in vitro because such studies require unambiguous detection of graft or host specific MHC class II genes. Although this is possible by using allele specific oligonucleotide probes for individual class II genes, such probes for class II genes in mice have not been described before. We compared the nucleotide sequences of I-As genes from various haplotypes and selected a region of minimal homology in the 2nd exon of this gene. We synthesized two oligonucleotide probes corresponding to a 20 nucleotide stretch in the hypervariable region of the I-As1 genes of H-2k and H-2d haplotype mice. These probes specifically detect I-As mRNA from mice of appropriate haplotypes. These allele-specific probes should help study the in vivo expression of graft or host specific I-A genes in G.V.H.R. or allograft reaction.