Role of Biased Gene Conversion in One-Locus Neutral Theory and Genome Evolution

AUTOR(ES)

Walsh, James Bruce

RESUMO

The implications of biased gene conversion acting on selectively neutral alleles are investigated for a single diallelic locus in a finite population. Even a very slight conversion bias can significantly alter fixation probabilities. We argue that most newly arising mutants will be at a conversion disadvantage, resulting in a potentially greatly decreased substitution rate of new alleles compared with predictions from strict neutral theory. Thus, conversion bias potential allows for conservation of particular alleles without having to invoke selection. Conversely, we also show that bias can be important in the maintenance of repeated gene families without altering the substitution rate at other loci that experience the same amount of conversion bias, provided that the number of genes in the family is sufficiently large. Bias can, therefore, be important at the genomic level and yet be unimportant at the populational level. Finally, we discuss the role of biased gene conversion in speciation events, concluding that this type of molecular turnover acting independently at many individual loci is very unlikely to decrease the time required for two allopatric populations to speciate.

Documentos Relacionados

• Parthenogenesis and Genetic Variability. II. One-Locus Models for Various Diploid Populations
• A Numerical Simulation of the One-Locus, Multiple-Allele Fertility Model
• Molecular clock of viral evolution, and the neutral theory.
• Interaction of selection and biased gene conversion in a multigene family.
• The Effect of Constraint on the Rate of Evolution in Neutral Models with Biased Mutation