标题：Spontaneous H-2 mutants provide evidence that a copy mechanism analogous to gene conversion generates polymorphism in the major histocompatibility complex
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1983
卷号：80
期号：1
页码：242-246
DOI：10.1073/pnas.80.1.242
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The analysis of H-2K products from spontaneously generated major histocompatibility complex (MHC) mutants and of the primary structure of other class I antigens suggests the genetic hypothesis that diversity in the MHC results from a copy mechanism analogous to gene conversion. The hypothesis was tested by making precise structural predictions about three partially characterized MHC mutants (bm1, bm3, and bm8). The predictions were based on consensus sequences among class I genes that differ from H-2Kb in the same region of the molecule as do the Kb mutants. In two cases (bm3 and bm8) we successfully predicted the correct amino acid substitution at positions known to be altered but for which the specific nature of the substitution had not been determined. In two additional cases (bm1 and bm8) we predicted and found both new mutation sites and the specific amino acid substitutions. The positions and identifications of the variant amino acids were determined by radiolabeled amino acid sequence analysis and DNA restriction endonuclease analysis. The interaction of MHC genes through a copy mechanism to generate diversity permits the introduction of multiple nucleotide base substitutions into class I sequences by a single genetic event. Such a mechanism may account in part for the large structural divergence among alleles of MHC loci and the high degree of MHC polymorphism among wild mice.
