The effect of deleterious mutations on neutral molecular variation
- PMID: 8375663
- PMCID: PMC1205596
- DOI: 10.1093/genetics/134.4.1289
The effect of deleterious mutations on neutral molecular variation
Abstract
Selection against deleterious alleles maintained by mutation may cause a reduction in the amount of genetic variability at linked neutral sites. This is because a new neutral variant can only remain in a large population for a long period of time if it is maintained in gametes that are free of deleterious alleles, and hence are not destined for rapid elimination from the population by selection. Approximate formulas are derived for the reduction below classical neutral values resulting from such background selection against deleterious mutations, for the mean times to fixation and loss of new mutations, nucleotide site diversity, and number of segregating sites. These formulas apply to random-mating populations with no genetic recombination, and to populations reproducing exclusively asexually or by self-fertilization. For a given selection regime and mating system, the reduction is an exponential function of the total mutation rate to deleterious mutations for the section of the genome involved. Simulations show that the effect decreases rapidly with increasing recombination frequency or rate of outcrossing. The mean time to loss of new neutral mutations and the total number of segregating neutral sites are less sensitive to background selection than the other statistics, unless the population size is of the order of a hundred thousand or more. The stationary distribution of allele frequencies at the neutral sites is correspondingly skewed in favor of rare alleles, compared with the classical neutral result. Observed reductions in molecular variation in low recombination genomic regions of sufficiently large size, for instance in the centromere-proximal regions of Drosophila autosomes or in highly selfing plant populations, may be partly due to background selection against deleterious mutations.
Similar articles
-
The pattern of neutral molecular variation under the background selection model.Genetics. 1995 Dec;141(4):1619-32. doi: 10.1093/genetics/141.4.1619. Genetics. 1995. PMID: 8601499 Free PMC article.
-
The effect of background selection against deleterious mutations on weakly selected, linked variants.Genet Res. 1994 Jun;63(3):213-27. doi: 10.1017/s0016672300032365. Genet Res. 1994. PMID: 8082838
-
The Effects on Neutral Variability of Recurrent Selective Sweeps and Background Selection.Genetics. 2019 May;212(1):287-303. doi: 10.1534/genetics.119.301951. Epub 2019 Mar 28. Genetics. 2019. PMID: 30923166 Free PMC article.
-
Background selection 20 years on: the Wilhelmine E. Key 2012 invitational lecture.J Hered. 2013 Mar;104(2):161-71. doi: 10.1093/jhered/ess136. Epub 2013 Jan 8. J Hered. 2013. PMID: 23303522 Review.
-
How can the low levels of DNA sequence variation in regions of the drosophila genome with low recombination rates be explained?Proc Natl Acad Sci U S A. 1994 Jul 19;91(15):6815-8. doi: 10.1073/pnas.91.15.6815. Proc Natl Acad Sci U S A. 1994. PMID: 8041702 Free PMC article. Review.
Cited by
-
Linked Selection and Gene Density Shape Genome-Wide Patterns of Diversification in Peatmosses.Evol Appl. 2024 Aug 19;17(8):e13767. doi: 10.1111/eva.13767. eCollection 2024 Aug. Evol Appl. 2024. PMID: 39165607 Free PMC article.
-
Population genetic structure in a self-compatible hermaphroditic snail is driven by drift independently of its contemporary mating system.Ecol Evol. 2024 Aug 13;14(8):e70162. doi: 10.1002/ece3.70162. eCollection 2024 Aug. Ecol Evol. 2024. PMID: 39139911 Free PMC article.
-
Impact of feralization on evolutionary trajectories in the genomes of feral cat island populations.PLoS One. 2024 Aug 13;19(8):e0308724. doi: 10.1371/journal.pone.0308724. eCollection 2024. PLoS One. 2024. PMID: 39137187 Free PMC article.
-
The recombination landscape of introgression in yeast.bioRxiv [Preprint]. 2024 Jul 9:2024.01.04.574263. doi: 10.1101/2024.01.04.574263. bioRxiv. 2024. PMID: 39026729 Free PMC article. Preprint.
-
Rolling down that mountain: microgeographical adaptive divergence during a fast population expansion along a steep environmental gradient in European beech.Heredity (Edinb). 2024 Aug;133(2):99-112. doi: 10.1038/s41437-024-00696-z. Epub 2024 Jun 18. Heredity (Edinb). 2024. PMID: 38890557 Free PMC article.
References
MeSH terms
LinkOut - more resources
Full Text Sources
Molecular Biology Databases