Open AccessRegions of Lower Crossing Over Harbor More Rare Variants in African Populations of Drosophila melanogaster
Author(s) -
Peter Andolfatto,
Molly Przeworski
Publication year - 2001
Publication title -
genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.792
H-Index - 246
eISSN - 1943-2631
pISSN - 0016-6731
DOI - 10.1093/genetics/158.2.657
Subject(s) - biology , fixation (population genetics) , drosophila melanogaster , background selection , genetics , negative selection , neutral mutation , recombination , evolutionary biology , chromosomal crossover , selection (genetic algorithm) , nucleotide diversity , drosophila (subgenus) , genome , allele , gene , haplotype , computer science , artificial intelligence
A correlation between diversity levels and rates of recombination is predicted both by models of positive selection, such as hitchhiking associated with the rapid fixation of advantageous mutations, and by models of purifying selection against strongly deleterious mutations (commonly referred to as "background selection"). With parameter values appropriate for Drosophila populations, only the first class of models predicts a marked skew in the frequency spectrum of linked neutral variants, relative to a neutral model. Here, we consider 29 loci scattered throughout the Drosophila melanogaster genome. We show that, in African populations, a summary of the frequency spectrum of polymorphic mutations is positively correlated with the meiotic rate of crossing over. This pattern is demonstrated to be unlikely under a model of background selection. Models of weakly deleterious selection are not expected to produce both the observed correlation and the extent to which nucleotide diversity is reduced in regions of low (but nonzero) recombination. Thus, of existing models, hitchhiking due to the recurrent fixation of advantageous variants is the most plausible explanation for the data.