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Immunogenetics2002; 54(5); 353-364; doi: 10.1007/s00251-002-0458-4

Evolution of the six horse IGHG genes and corresponding immunoglobulin gamma heavy chains.

Abstract: It is generally assumed that the different mammalian IgG isotypes have developed during evolution by duplications of a common ancestor gamma heavy chain constant region gene (IGHG). In contrast to other species studied so far, which express between one and four IGHG genes, the horse (Equus caballus) genome contains six IGHG genes, and it has been postulated that they all can be expressed. For determination of the evolutionary history of the six horse IGHG genes, genomic DNA and cDNA of the IGHG genes were sequenced. The structure of these genes with reference to exons and introns was determined. Comparison of the deduced amino acid sequences of the horse IGHG genes revealed the greatest divergences in the hinge regions, and in the proximal CH2 domains. A phylogenetic comparison of the amino acid sequences of the six horse IGHG genes to those of other species shows that the horse IGHG genes form a distinct cluster. This indicates that the mammalian species included in this study probably share only one common ancestor IGHG gene with the horse. The six horse IGHG genes probably then evolved by gene duplication after species separation. In addition, various segmental exchanges were found between the horse IGHG genes, which might be the result of unequal crossing over and/or gene conversion events during the evolution of the six horse IGHG genes.
Publication Date: 2002-07-04 PubMed ID: 12185539DOI: 10.1007/s00251-002-0458-4Google Scholar: Lookup
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  • Comparative Study
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

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The research paper examines the history and development of the six IGHG genes in horses, which are responsible for creating immunoglobulin G (IgG) proteins.

Evolutionary Examination of IGHG Genes in Horses

The researchers aim to trace the evolutionary history of the six IGHG genes found in the horse genome. Other mammals typically express between one and four of these genes, which encode the IgG proteins, critical components of the immune response system. The researchers sequenced the genomic DNA and cDNA of these horse IGHG genes, and their structure was also examined.

  • A substantial divergence was observed in the hinge regions and the proximal CH2 domains of the horse IGHG genes.
  • The detailed comparison confirmed the major variances happening in the mentioned areas.

Phylogenetic Comparison of Horse IGHG Genes with Other Species

Researchers undertook a thorough comparison of the amino acid sequences of the six horse IGHG genes with those found in other species. The objective was to reveal any relationships or shared ancestral genes.

  • The amino acid sequences of the six horse IGHG genes formed a distinct cluster, highlighting their unique evolutionary path.
  • It was posited that the species in the study probably only share one common ancestor IGHG gene with the horse.
  • The researchers suggest that the six horse IGHG genes evolved from this single gene through a duplicated after the species had separated.

Evolutionary Events Impacting Horse IGHG Genes

The researchers then considered the progression of the six horse IGHG genes, based on their distinct clustering.

  • The researchers hypothesized that several segmental exchanges occurred between these genes during their evolution.
  • They proposed that these exchanges could result from unequal crossing over and/or gene conversion events.
  • Such genetic events could explain further about the unique evolution and functionality of the six IGHG genes in the horse genome.

Cite This Article

APA
Wagner B, Greiser-Wilke I, Wege AK, Radbruch A, Leibold W. (2002). Evolution of the six horse IGHG genes and corresponding immunoglobulin gamma heavy chains. Immunogenetics, 54(5), 353-364. https://doi.org/10.1007/s00251-002-0458-4

Publication

ISSN: 0093-7711
NlmUniqueID: 0420404
Country: United States
Language: English
Volume: 54
Issue: 5
Pages: 353-364

Researcher Affiliations

Wagner, Bettina
  • Immunology Unit, School of Veterinary Medicine, Hannover, Germany. bw73@cornell.edu
Greiser-Wilke, Irene
    Wege, Anja K
      Radbruch, Andreas
        Leibold, Wolfgang

          MeSH Terms

          • Amino Acid Sequence
          • Animals
          • Binding Sites
          • Evolution, Molecular
          • Genes, Immunoglobulin
          • Horses / genetics
          • Horses / immunology
          • Immunoglobulin Constant Regions / genetics
          • Immunoglobulin G / genetics
          • Immunoglobulin Heavy Chains / genetics
          • Immunoglobulin Isotypes / genetics
          • Mammals / genetics
          • Molecular Sequence Data
          • Phylogeny
          • Protein Structure, Tertiary
          • Receptors, IgG / metabolism
          • Species Specificity

          Citations

          This article has been cited 8 times.
          1. Li L, Rong X, Li G, Wang Y, Chen B, Ren W, Yang G, Xu S. Genomic organization and adaptive evolution of IGHC genes in marine mammals. Mol Immunol 2018 Jul;99:75-81.
            doi: 10.1016/j.molimm.2018.04.011pubmed: 29723770google scholar: lookup
          2. Sun Y, Liu Z, Ren L, Wei Z, Wang P, Li N, Zhao Y. Immunoglobulin genes and diversity: what we have learned from domestic animals. J Anim Sci Biotechnol 2012 Jun 20;3(1):18.
            doi: 10.1186/2049-1891-3-18pubmed: 22958617google scholar: lookup
          3. Mealey RH, Kappmeyer LS, Ueti MW, Wagner B, Knowles DP. Protective effects of passively transferred merozoite-specific antibodies against Theileria equi in horses with severe combined immunodeficiency. Clin Vaccine Immunol 2012 Jan;19(1):100-4.
            doi: 10.1128/CVI.05301-11pubmed: 22038847google scholar: lookup
          4. Guo Y, Bao Y, Wang H, Hu X, Zhao Z, Li N, Zhao Y. A preliminary analysis of the immunoglobulin genes in the African elephant (Loxodonta africana). PLoS One 2011 Feb 25;6(2):e16889.
            doi: 10.1371/journal.pone.0016889pubmed: 21364892google scholar: lookup
          5. Al-Swailem AM, Shehata MM, Abu-Duhier FM, Al-Yamani EJ, Al-Busadah KA, Al-Arawi MS, Al-Khider AY, Al-Muhaimeed AN, Al-Qahtani FH, Manee MM, Al-Shomrani BM, Al-Qhtani SM, Al-Harthi AS, Akdemir KC, Inan MS, Otu HH. Sequencing, analysis, and annotation of expressed sequence tags for Camelus dromedarius. PLoS One 2010 May 19;5(5):e10720.
            doi: 10.1371/journal.pone.0010720pubmed: 20502665google scholar: lookup
          6. Lewis MJ, Meehan M, Owen P, Woof JM. A common theme in interaction of bacterial immunoglobulin-binding proteins with immunoglobulins illustrated in the equine system. J Biol Chem 2008 Jun 20;283(25):17615-23.
            doi: 10.1074/jbc.M709844200pubmed: 18411272google scholar: lookup
          7. Lewis MJ, Wagner B, Woof JM. The different effector function capabilities of the seven equine IgG subclasses have implications for vaccine strategies. Mol Immunol 2008 Feb;45(3):818-27.
            doi: 10.1016/j.molimm.2007.06.158pubmed: 17669496google scholar: lookup
          8. Wagner B, Greiser-Wilke I, Antczak DF. Characterization of the horse (Equus caballus) IGHA gene. Immunogenetics 2003 Nov;55(8):552-60.
            doi: 10.1007/s00251-003-0617-2pubmed: 14564492google scholar: lookup