Ancient roots for polymorphism at the HLA-DQ. alpha. locus in primates

Journal Article · Fri Dec 01 00:00:00 EST 1989 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.86.24.9986· OSTI ID:6969583

Gyllensten, U B; Erlich, H A ^[1]

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1. Cetus Corp., Emeryville, CA (USA)

The genes encoding the human histocompatibility antigens (HLA) exhibit a remarkable degree of polymorphism as revealed by immunologic and molecular analyses. This extensive sequence polymorphism either may have been generated during the lifetime of the human species or could have arisen before speciation and been maintained in the contemporary human population by selection or, possibly, by genetic drift. These two hypotheses were examined using the polymerase chain reaction method to amplify polymorphic sequences from the DQ{alpha} locus, as well as the DX{alpha} locus, an homologous but nonexpressed locus, in a series of primates that diverged at known times. In general, the amino acid sequence of a specific human DQ{alpha} allelic type is more closely related to its chimpanzee or gorilla counterpart than to other human DQ{alpha} alleles. Phylogenetic analysis of the silent nucleotide position changes shows that the similarity of allelic types between species is due to common ancestry rather than convergent evolution. Thus, most of the polymorphism at the DQ{alpha} locus in the human species was already present at least 5 million years ago in the ancestral species that gave rise to the chimpanzee, gorilla, and human lineages. However, one of the DQ{alpha} alleles may have arisen after speciation by recombination between two ancestral alleles.

• OSTI ID: 6969583
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 86:24; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANTIGENS
AMINO ACID SEQUENCE
HISTOCOMPATIBILITY COMPLEX
BIOLOGICAL EVOLUTION
RFLPS
DNA SEQUENCING
DNA POLYMERASES
GENE RECOMBINATION
MAN
PRIMATES
ANIMALS
ENZYMES
MAMMALS
MOLECULAR STRUCTURE
NUCLEOTIDYLTRANSFERASES
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
STRUCTURAL CHEMICAL ANALYSIS
TRANSFERASES
VERTEBRATES
550400* - Genetics