Theoretical study on the accumulation of selfish DNA

Abstract

SUMMARY: The accumulation of selfish DNA in eukaryotic genomes was studied from the standpoint of population genetics. Selfish DNA is assumed to replicate itself within a haploid set. For the selectively neutral case, the fate of a single self-replicating DNA segment (unit) within a population was investigated by the method of the probability generating function, and by Monte Carlo simulation, with special reference to the probability of survival and average number of units per haploid set. For the selectively deleterious case at the organismal level, the equilibrium between new occurrence and selective elimination was studied, and the average and variance of the number of units per haploid set in the population was examined by Monte Carlo simulation. It is shown that the process of self-replication (duplication–deletion) plays an essential role for the maintenance and elimination of selfish DNA.