Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-20T01:05:00.265Z Has data issue: false hasContentIssue false

Genetic variance and fixation probabilities at quantitative trait loci in mutation-selection balance

Published online by Cambridge University Press:  14 April 2009

Peter D. Keightley
Affiliation:
Institute of Cell Animal and Population Biology, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, Scotland
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Genetic variance and fixation probabilities are evaluated for a model of a quantitative trait at a balance between mutation, selection and drift in which many alleles can segregate at each locus. If the distribution of effects of new mutant alleles is such that mutations are unconditionally deleterious, as might be the case in natural populations, genetic variance maintained is proportional to the number of mutations occurring in the genome per generation, but is independent of the number of loci at which they appear. If selectively advantageous alleles can occur these tend to interfere to a greater extent with each others' fixation and increasing mutation rate leads to a decrease in the genetic variance as a fraction of the variance maintained in the absence of selection. Fixation probabilities of new mutant alleles approach that for neutral alleles with increasing mutation rate at a locus irrespective of their effects on fitness. The additive genetic variance contributed by the locus may appear to be ‘decoupled’ from the fixation rate of mutant alleles.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1991

References

Birky, C. W. & Walsh, J. B. (1988). Effect of linkage on molecular evolution. Proceedings of the National Academy of Sciences, USA 85, 64146418.CrossRefGoogle ScholarPubMed
Bulmer, M. G. (1972). Genetic variability of polygenic characters under optimizing selection, mutation and drift. Genetic Research 19, 1725.CrossRefGoogle ScholarPubMed
Bulmer, M. G. (1980). The Mathematical Theory of Quantitative Genetics. Oxford: Clarendon Press.Google Scholar
Bulmer, M. G. (1989). Maintenance of genetic variability by mutation–selection balance: a child's guide through the jungle. Genome 31, 761767.CrossRefGoogle Scholar
Cockerham, C. C. & Tachida, H. (1987). Evolution and maintenance of quantitative genetic variation by mutations. Proceedings of the National Academy of Sciences, USA 84, 62056209.CrossRefGoogle ScholarPubMed
Foley, P. (1987). Molecular clock rates at loci under stabilizing selection. Proceedings of the National Academy of Sciences, USA 84, 79968000.CrossRefGoogle ScholarPubMed
Hill, W. G. (1982). Rates of change in quantitative traits from fixation of new mutations. Proceedings of the National Academy of Sciences, USA 79, 142145.CrossRefGoogle ScholarPubMed
Hill, W. G. & Robertson, A. (1966). The effects of linkage on limits to artificial selection. Genetical Research 8, 269294.CrossRefGoogle ScholarPubMed
Keightley, P. D. & Hill, W. G. (1990). Variation maintained in quantitative traits with mutation-selection balance: pleiotropic side-effects on fitness traits. Proceedings of the Royal Society of London Series B 242, 95100.Google Scholar
Kimura, M. (1957). Some problems of stochastic processes in genetics. Annals of Mathematical Statistics 28, 882901.CrossRefGoogle Scholar
Kimura, M. (1965). A stochastic model concerning the maintenance of genetic variability in quantitative characters. Proceedings of the National Academy of Sciences, USA 54, 731736.CrossRefGoogle ScholarPubMed
Kimura, M. (1969). The number of heterozygous nucleotide sites maintained in a finite population due to a steady flux of mutations. Genetics 61, 893903.CrossRefGoogle Scholar
Kimura, M. (1983). The Neutral Theory of Molecular Evolution. Cambridge University Press.CrossRefGoogle Scholar
Lande, R. (1976). The maintenance of genetic variability by mutation in a polygenic character with linked loci. Genetical Research 26, 221235.CrossRefGoogle Scholar
Lande, R. (1980). The genetic covariance of characters maintained by pleiotropic mutations. Genetics 94, 203215.CrossRefGoogle ScholarPubMed
Leigh, Brown A. J. (1989). Population Genetics at the DNA level: a review of the contribution of restriction enzyme studies. Oxford Surveys in Evolutionary Biology 6, 207242.Google Scholar
Robertson, A. (1956). The effect of selection against extreme deviants based on deviation or on homozygosis. Journal of Genetics 54, 236248.CrossRefGoogle Scholar
Slatkin, M. (1987). Heritable variation and heterozygosity under a balance between mutations and stabilizing selection. Genetical Research 50, 5362.CrossRefGoogle Scholar
Turelli, M. (1984). Heritable genetic variation via mutation–selection balance: Lerch's zeta meets the abdominal bristle. Theoretical Population Biology 25, 138193.CrossRefGoogle Scholar