Limited MHC Polymorphism in the Southern Elephant Seal: Implications for MHC Evolution and Marine Mammal Population Biology

Genes of the major histocompatibility complex (MHC) are highly polymorphic in most terrestrial mammal populations so far studied. Exceptions to this are typically populations that lack genome-wide diversity. Here I show that two populations of the southern elephant seal (Mirounga leonina) have low D...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the Royal Society. B, Biological sciences Biological sciences, 1992-08, Vol.249 (1325), p.163-171
Main Author: Slade, Robert W.
Format: Article
Language:English
Subjects:
Animals
Biological Evolution
DNA
DNA - genetics
DNA - isolation & purification
Elephants
Enzymes
Genetic loci
Humans
Major Histocompatibility Complex
Major histocompatibility complex genes
Mammals
Mammals - genetics
Mammals - immunology
Marine mammals
Polymorphism, Restriction Fragment Length
Population
Restriction Mapping
Seals
Seals, Earless - genetics
Seals, Earless - immunology
Seawater
Whales
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Genes of the major histocompatibility complex (MHC) are highly polymorphic in most terrestrial mammal populations so far studied. Exceptions to this are typically populations that lack genome-wide diversity. Here I show that two populations of the southern elephant seal (Mirounga leonina) have low DNA restriction fragment length polymorphism at MHC loci when compared with terrestrial mammals. Limited studies on MHC polymorphism in two cetacean species suggest this is a feature of marine mammal populations in general, MHC polymorphism is thought to be maintained by balancing selection, and several types of disease-based and reproductive-based mechanisms have been proposed. For the three marine mammal species examined, the low mhc polymorphism cannot be explained by low genome-wide diversity, or by any reproductive-based selection pressure. It can, however, be explained by diminished exposure to pathogenic selection pressure compared with terrestrial mammals. Reduced exposure to pathogens would also mean that marine mammal populations may be susceptible to occasional pathogeninduced mass mortalities.
ISSN:0962-8452
1471-2954
DOI:10.1098/rspb.1992.0099