Limited polymorphism at major histocompatibility complex (MHC) loci in the Swedish moose A. alces

Authors

  • H. ELLEGREN,

    Corresponding author
    1. Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Biomedical Centre, Box 597, S-751 24 Uppsala
      Fax: +46 18 504461. E-mail: Hans.Ellegren@bmc.uu.se
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  • S. MIKK,

    1. Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Biomedical Centre, Box 597, S-751 24 Uppsala
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  • K. WALLIN,

    1. *Department of Animal Ecology, Swedish University of Agricultural Sciences, S-901 83 Umed, Sweden
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  • L. ANDERSSON

    1. Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Biomedical Centre, Box 597, S-751 24 Uppsala
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  • This work is a part of Elisabetta Giuffra's PhD thesis on the geographical variation at protein loci and mtDNA in the S. trutta complex from Northern Italy. René Guyomard is a population geneticist at the Laboratory of Fish Genetics of INRA. This laboratory is involved in research programs on conservation, management and selective breeding of freshwater fish species. Gilberto Forneris is ichthyologist at the Dipartimento di Produzioni Animali, Epidemiologia ed Ecologia of the University of Turino and is responsible for programs of conservation of natural population of freshwater fish in the Piemonte Province.

Fax: +46 18 504461. E-mail: Hans.Ellegren@bmc.uu.se

Abstract

The Swedish moose was analysed for genetic variability at major histocompatibility complex (MHC) class I and class II DQA, DQB and DRB loci using restriction fragment length polymorphism (RFLP) and single strand conformation polymorphism (SSCP) techniques. Both methods revealed limited amounts of polymorphism. Since the SSCP analysis concerned an expressed DRB gene it can be concluded that the level of functional MHC class II polymorphism, at least at the DRB locus, is low in Swedish moose. DNA fingerprinting was used to determine if the unusual pattern of low MHC variability could be explained by a low degree of genome-wide genetic diversity. Hybridizations with two minisatellite probes gave similarity indices somewhat higher than the average for other natural population, but the data suggest that the low MHC variability cannot be explained by a recent population bottleneck. However, since minisatellite sequences evolve more rapidly than MHC sequences, the low levels of MHC diversity may be attributed to a bottleneck of more ancient origin. The selection pressure for MHC variability in moose may also be reduced and we discuss the possibility that its solitary life style may reduce lateral transmission of pathogens in the population.

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