Immunogenetics

, Volume 62, Issue 2, pp 85–100

Major histocompatibility complex variation and evolution at a single, expressed DQA locus in two genera of elephants

Authors

    • Center for Conservation and Evolutionary Genetics, National Zoological Park & National Museum of Natural HistorySmithsonian Institution
    • Department of Biological SciencesUniversity of Notre Dame
  • Tammy Henry
    • Center for Conservation and Evolutionary Genetics, National Zoological Park & National Museum of Natural HistorySmithsonian Institution
    • Department of Environmental Science and PolicyGeorge Mason University
  • Jesus E. Maldonado
    • Center for Conservation and Evolutionary Genetics, National Zoological Park & National Museum of Natural HistorySmithsonian Institution
  • Cynthia J. Moss
    • Amboseli Trust for Elephants
  • Joyce H. Poole
    • Amboseli Trust for Elephants
  • Virginia R. Pearson
    • Philadelphia Zoo
  • Suzan Murray
    • Animal HealthNational Zoological Park
  • Susan C. Alberts
    • Department of BiologyDuke University
  • Robert C. Fleischer
    • Center for Conservation and Evolutionary Genetics, National Zoological Park & National Museum of Natural HistorySmithsonian Institution
Original Paper

DOI: 10.1007/s00251-009-0413-8

Cite this article as:
Archie, E.A., Henry, T., Maldonado, J.E. et al. Immunogenetics (2010) 62: 85. doi:10.1007/s00251-009-0413-8

Abstract

Genes of the vertebrate major histocompatibility complex (MHC) are crucial to defense against infectious disease, provide an important measure of functional genetic diversity, and have been implicated in mate choice and kin recognition. As a result, MHC loci have been characterized for a number of vertebrate species, especially mammals; however, elephants are a notable exception. Our study is the first to characterize patterns of genetic diversity and natural selection in the elephant MHC. We did so using DNA sequences from a single, expressed DQA locus in elephants. We characterized six alleles in 30 African elephants (Loxodonta africana) and four alleles in three Asian elephants (Elephas maximus). In addition, for two of the African alleles and three of the Asian alleles, we characterized complete coding sequences (exons 1–5) and nearly complete non-coding sequences (introns 2–4) for the class II DQA loci. Compared to DQA in other wild mammals, we found moderate polymorphism and allelic diversity and similar patterns of selection; patterns of non-synonymous and synonymous substitutions were consistent with balancing selection acting on the peptides involved in antigen binding in the second exon. In addition, balancing selection has led to strong trans-species allelism that has maintained multiple allelic lineages across both genera of extant elephants for at least 6 million years. We discuss our results in the context of MHC diversity in other mammals and patterns of evolution in elephants.

Keywords

African elephantAsian elephantDQAMajor histocompatibility complexCoding sequenceMolecular evolution

Copyright information

© Springer-Verlag 2009