Evolutionary dynamics of non-coding sequences within the class II region of the human MHC.
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.
Beck
S
S
DNA Sequencing Laboratory, Imperial Cancer Research Fund, London, England.
Abdulla
S
S
Alderton
R P
RP
Glynne
R J
RJ
Gut
I G
IG
Hosking
L K
LK
Jackson
A
A
Kelly
A
A
Newell
W R
WR
Sanseau
P
P
Radley
E
E
Thorpe
K L
KL
Trowsdale
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001482:Base Composition; D001483:Base Sequence / Q000235:genetics; D019143:Evolution, Molecular; D005802:Genes, MHC Class II / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011544:Pseudogenes / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity