| 要旨 |
Linkage disequilibrium, or nonrandom association of alleles at different loci, may be established through a number of population processes; random genetic drift, demographic history, geographic structure, and so on. Epistatic interaction among functionally related genes might also generate linkage disequilibrium, but empirical studies have rarely found significant deviations from the expectation of independent gene action. Focusing on the theoretical expectation that the evolution should generate linkage disequilibrium when genes interact epistatically, we here investigate the consequences of epistatic interaction for fitness on the amount of linkage disequilibrium between loosely linked loci. Stochastic models of polygenic systems are formulated to see how synergistic/antagonistic epistasis among deleterious mutations should promote the formation of linkage disequilibrium in a panmictic population of a finite size. Based on the simulation results, we will discuss the prospects for elucidating functionally interacting biological systems from available linkage disequilibrium data.
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