Intergenic regions contribute fitness advance by increasing recombination

Intergenic regions are common in eukaryotic genomes, yet they often appear to confer no direct fitness advantage. This study hypothesized that the primary function of these regions may be to enhance the frequency of meiotic recombination between genes, thereby reducing selective interference and improving the efficacy of selection. To test this hypothesis, computer simulations were conducted using the slim4 software to examine the impact of varying lengths of intergenic regions on total fitness. Populations with extended intergenic regions exhibited increased total fitness. Notably, the average fitness effects of both advantageous and deleterious mutations diminished, implying an enhanced selection efficiency, particularly for mutations with marginal fitness impacts. Total fitness effect of deleterious mutations increased despite the average fitness effect decreasing. Linkage between deleterious mutations could contribute to purging of slightly deleterious mutations.These results underscore the need for a more comprehensive examination of the relationship between recombination and intergenic regions to fully elucidate their evolutionary significance and contribution to genomic architecture. Article SummaryEvolutionary significance of intergenic regions are still unclear. This study hypothesized that the primary function of these regions may be to enhance the frequency of meiotic recombination between genes, thereby reducing selective interference and improving the efficacy of selection. The simulation showed that populations with extended intergenic regions exhibited increased total fitness. The results poin t the way for future research about evolution of intergenic regions and the effect of genomic position of genes.