Comparative genomics of the MHC: glimpses into the evolution of the adaptive immune system

Immunity. 2001 Sep;15(3):351-62. doi: 10.1016/s1074-7613(01)00198-4.


MHC gene organization (size, complexity, gene order) differs markedly among different species, and yet all nonmammalian vertebrates examined to date have a true "class I region" with tight linkage of genes encoding the class I presenting and processing molecules. Three paralogous regions of the human genome contain sets of linked genes homologous to various loci in the MHC class I, class II, and/or class III regions, providing insight into the organization of the "proto MHC" before the emergence of the adaptive immune system in the jawed vertebrates.

MeSH terms

  • Adaptation, Physiological
  • Animals
  • Biological Evolution
  • Genes, MHC Class I
  • Genes, MHC Class II
  • Genome, Human
  • Genomics*
  • Humans
  • Immune System / physiology*
  • Major Histocompatibility Complex*