Interchromosomal biased gene conversion, mutation and selection in a multigene family

Area of Science:

• Population Genetics
• Molecular Evolution
• Mathematical Biology

Background:

• Multigene families are crucial for evolution.
• Gene conversion, mutation, and selection are key evolutionary forces.
• Understanding interchromosomal vs. intrachromosomal conversion is vital.

Purpose of the Study:

• To model the effects of interchromosomal biased gene conversion, mutation, and natural selection on multigene families.
• To analyze the equilibrium dynamics of these forces, ignoring genetic drift.
• To compare the impact of interchromosomal and intrachromosomal conversion.

Main Methods:

• Developed a mathematical model for n loci with two allelic states.
• Analyzed the model at equilibrium, considering no initial recombination.
• Investigated the balance between mutation, gene conversion, and selection.

Main Results:

• Equilibrium analysis showed no linkage disequilibrium, validating conclusions for any recombination rate.
• Allele fixation is likely when selection and conversion advantages outweigh mutation rates.
• Interchromosomal biased conversion is more potent than intrachromosomal conversion for allele substitution.

Conclusions:

• Interchromosomal biased gene conversion significantly impacts allele frequencies in multigene families.
• The relative strength of inter- and intrachromosomal conversion can be inferred from linkage disequilibrium.
• Mathematical modeling provides insights into the evolutionary dynamics of gene families.