Stability of genetic polymorphism in host-parasite interactions.

ABSTRACT: Allelic diversity is common at host loci involved in parasite recognition, such as the major histocompatibility complex in vertebrates or gene-for-gene relationships in plants, and in corresponding loci encoding antigenic molecules in parasites. Diverse factors have been proposed in models to account for genetic polymorphism in host-parasite recognition. Here, a simple but general theory of host-parasite coevolution is developed. Coevolution implies the existence of indirect frequency-dependent selection (FDS), because natural selection on the host depends on the frequency of a parasite gene, and vice versa. It is shown that polymorphism can be maintained in both organisms only if there is negative, direct FDS, such that the strength of natural selection for the host resistance allele, the

SUBMITTER: Tellier A 

PROVIDER: S-EPMC2093977 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature