HLA—B与TNF基因间区的单体型特异性的多态现象

Haplotype-Specific Polymorphism Between HLA-B and Tumor Necrosis Factor

Abstract Polymorphism was defined between HLA-B and TNF using three genomic probes. Extensive polymorphism was detected within a panel of 50 cell lines inducing 37 homozygotes representing 21 different ancestral haplotypes (AH). Following Taq I digestion of genomic DNA.we observed 3 allelic patterns with probe XCR17) and 4 with probe V(R9A) and different allelic patterns with probe Y(M20A) after Taq I + Rsa I digestion. Family studies showed that the Y.X and V alleles were inherited and segregated with HLA haplotypes. A striking feature of the allelic patterns detected by these probes was that cells with the same AH had identical Y,X and V alleles(i. e,the alleles were haplotypic). Of 15 different Y-X-V haplotypes observed. 11 were found to be specific for a particular AH (i.e. were haplotype specific). Four were shared by more than one AH but in these cases there were extensive simiarities in other regions within the MHC. The present study confirms that MHC AHs have been conserved en bloc including the region between HLA-B and TNF.