Neutral effect of recombination on base composition in Drosophila.

Recombination is thought to have various evolutionary effects on genome evolution. In this study, we investigated the relationship between the base composition and recombination rate in the Drosophila melanogaster genome. Because of a current debate about the accuracy of the estimates of recombination rate in Drosophila, we used eight different measures of recombination rate from recent work. We confirmed that the G + C content of large introns and flanking regions is positively correlated with recombination rate, suggesting that recombination has a neutral effect on base composition in Drosophila. We also confirmed that this neutral effect of recombination is the main determinant of the correlation between synonymous codon usage bias and recombination rate in Drosophila.