Evolutionary dynamics of non-coding sequences within the class II region of the human MHC.
Beck S,
Abdulla S,
Alderton RP,
Glynne RJ,
Gut IG,
Hosking LK,
Jackson A,
Kelly A,
Newell WR,
Sanseau P,
Radley E,
Thorpe KL,
Trowsdale J.
DNA Sequencing Laboratory, Imperial Cancer Research Fund, London, England.
About 40% (350 kb) of the human MHC class II region has been sequenced and a coordinated effort to sequence the entire MHC is underway. In addition to the coding information (22 genes/pseudogenes), the non-coding sequences reveal novel information on the organisation and evolution of the MHC as demonstrated here by the example of a 200 kb contig that has been analysed for local and global features. In conjunction with cross-species comparisons, our results present new evidence on the structure of isochores, the evolutionary dynamics of repeat-mediated recombination and its effect on certain MHC encoded genes, and a higher than average degree of natural polymorphism that has implications for sequencing the human genome. We also report the finding of a class I-related pseudogene (HLA-ZI) in the middle of the class II region, which provides the first direct evidence for DNA exchange between these two related regions in man.
PMID: 8568858 [PubMed - indexed for MEDLINE]