Vertebrate Immune System: Evolution

Austin L Hughes, University of South Carolina, Columbia, South Carolina, USA

Published online: May 2008

DOI: 10.1002/9780470015902.a0006125.pub2

The vertebrates possess unique adaptations for immune defense that have apparently evolved gradually over the long evolutionary history of the vertebrate lineage. Molecular diversity is one of the hallmarks of vertebrate immune mechanisms, and molecular analyses have clearly implicated natural selection as the major factor in promoting molecular diversity and a consequent enhanced immune surveillance.

Keywords: immune system; immunoglobulin; innate immunity; major histocompatibility complex; NF-B

Figure 1. Schematic phylogeny of the chordates, indicating the time of origin of molecules involved in specific immunity in vertebrates. Ig: immunoglobulin; MHC: major histocompatibility complex; Myr: million years; TCR: T-cell receptors.
Figure 2. Phylogeny of the Toll family of receptors from insects and vertebrates TLR: Toll-like receptor; dG=amino acid distance (corrected for multiple hits on the assumption that rates vary among sites following of gamma distribution). (Reproduced with permission from Friedman and Hughes, 2002.)
Figure 3. Mean numbers of synonymous (dS) and nonsynonymous (dN) nucleotide substitutions per site in comparisons between orthologous human and rodent immunoglobulin superfamily C2-set domains. N: number of genes compared. (Adapted with permission from Hughes, 1997.)
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 References
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    Hughes AL (1997) Rapid evolution of immunoglobulin superfamily C2 domains expressed in immune system cells. Molecular Biology and Evolution 14: 1–5.
    Hughes AL (1999a) Genomic catastrophism and the origin of vertebrate immunity. Archivum Immunologiae et Therapiae Experimentalis 47: 347–353.
    Hughes AL (1999b) Evolutionary diversification of the mammalian defensins. Cellular and Molecular Life Sciences 56: 94–103.
    Hughes AL and Nei M (1988) Pattern of nucleotide substitution at class I MHC loci reveals overdominant selection. Nature 335: 167–170.
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 Further Reading
    Cooper MD and Alder MN (2006) The evolution of adaptive immune systems. Cell 124: 815–822.
    Du Pasquier L (2004) Speculations on the origin of the vertebrate immune system. Immunology Letters 92: 3–9.
    Flajnik MF and Du Pasquier L (2004) Evolution of innate and adaptive immunity: can we draw a line? Trends in Immunology 25: 640–644.
    Hughes AL (1998) Protein phylogenies provide evidence of a radical discontinuity between arthropod and vertebrate immune systems. Immunogenetics 47: 283–296.
    book Hughes AL (1999) Adaptive Evolution of Genes and Genomes. New York: Oxford University Press.
    Hughes AL (2002) Natural selection and the diversification of vertebrate immune effectors. Immunological Reviews 190: 161–168.
    book Klein J and Hoejší V (1998) Immunology, 2nd edn. Oxford, UK: Blackwell Scientific.
    Litman GW, Cannon JP and Dishaw LJ (2005) Reconstructing immune phylogeny: new perspectives. Nature Reviews Immunology 5: 866–879.
    Rast JP, Smith LC, Loza-Coll M, Hibino T and Litman GW (2006) Genomic insights into the immune system of the sea urchin. Science 314: 952–956.
 Web Links
    ePath recombination activating gene 1 (RAG1); LocusID: 5896. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=5896
    ePath recombination activating gene 2 (RAG2); LocusID: 5897. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=5897
    ePath recombination activating gene 1 (RAG1); MIM number: 179615. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?179615
    ePath recombination activating gene 2 (RAG2); MIM number: 179616. OMIM: http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?179616

Related Sub-Topics:

Acquired (Adaptive) Immunity | Innate Immunity | Adaptive Evolution | Evolution of Novelty | Molecular Evolution | Protein Evolution | Evolution of Coding and Functional Modules
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Article Title: Vertebrate Immune System: Evolution
 
How to Cite close
Hughes, Austin L(May 2008) Vertebrate Immune System: Evolution. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0006125.pub2]