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Detrimental genes with partial selfing and effects on a neutral locus*

Published online by Cambridge University Press:  14 April 2009

Tomoko Ohta
Affiliation:
Department of Statistics, North Carolina State UniversityRaleigh, North Carolina 27607
C. Clark Cockerham
Affiliation:
Department of Statistics, North Carolina State UniversityRaleigh, North Carolina 27607
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Summary

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Gene and genotypic frequencies for a deleterious mutant in mutation selection balance are derived for an infinite population undergoing partial self-fertilization. These provide formulations of mean survival and the mutational load. Obtained also are the average number of mutant genes and affected individuals stemming from a single mutant.

As a concomitant effect on frequencies at a neutral locus the mutational load is distributed disproportionately among the neutral genotypes. For partially recessive mutant genes on the 1, 1-sh, 1-s scale, the effect is to increase the frequency of the heterozygote and to decrease the frequencies of homozygotes at the neutral locus relative to the frequencies expected with complete neutrality. This apparent overdominance at the neutral locus has been shown to be connected with identity disequilibrium rather than linkage disequilibrium. It increases generally as s and h decrease, and as the proportion of self-fertilization and the degree of linkage increase. The apparent overdominance with complete linkage is generally less than double that for free recombination. For partially dominant mutant genes, h ≥ ½, the effects on the frequencies of heterozygote and homozygotes at the neutral locus are reversed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1974

References

REFERENCES

Allard, R. W., Kahler, A. L. & Weir, B. S. (1972). The effect of selection on esterase allozymes in a barley population. Genetics 72, 489503.Google Scholar
Allard, R. W. & Workman, P. L. (1963). Population studies in predominantly self-pollinated species. IV. Seasonal fluctuations in estimated values of genetic parameters in lima bean populations. Evolution 17, 470480.Google Scholar
Cockerham, C. Clark & Rawlings, J. O. (1967). Apparent heterosis of a neutral gene with inbreeding. Ciencia E Cultura 19, 8994.Google Scholar
Comstock, R. E. & Robinson, H. F. (1952). Estimation of average dominance of genes. Heterosis, pp. 494516. Ames: Iowa State College Press.Google Scholar
Frydenberg, O. (1963). Population studies of a lethal mutant in Drosophila melanogaster. I. Behaviour in populations with discrete generations. Hereditas 50, 89116.CrossRefGoogle Scholar
Hamrick, J. L. & Allard, R. W. (1972). Microgeographical variation in allozyme frequencies in Avena barbata. Proceedings of the National Academy of Sciences U.S.A. 69, 21002104.Google Scholar
Hill, W. G. (1968). Population dynamics of linked genes in finite populations. Proceedings of the XII International Congress of Genetics Vol. 2, 146147.Google Scholar
Jain, S. K. & Allard, R. W. (1960). Population studies in predominantly self-pollinated species, I. Evidence for heterozygote advantage in a closed population of barley. Proceedings of the National Academy of Sciences U.S.A. 46, 13711377.CrossRefGoogle Scholar
Li, Wen-Hsiung & Nei, Masatoshi (1972). Total number of individuals affected by a single deleterious mutation in a finite population. The American Journal of Human Genetics 24, 667679.Google Scholar
Marshall, D. R. & Allard, R. W. (1970). Maintenance of isozyme polymorphisms in natural populations of Avena barbata. Genetics 66, 393399.Google Scholar
Maruyama, T. & Kimura, M. (1968). Development of temporary overdominance associated with neutral alleles. Proceedings of the XII International Congress of Genetics Vol. 1, 229.Google Scholar
Ohta, Tomoko (1971). Associative overdominance caused by linked detrimental mutations. Genetical Research 18, 277286.Google Scholar
Ohta, Tomoko & Kimura, Motoo (1969). Linkage disequilibrium at steady state determined by random genetic drift and recurrent mutation. Genetics 63, 229238.Google Scholar
Ohta, Tomoko & Kimura, Motoo (1970). Development of associative overdominance through linkage disequilibrium in finite populations. Genetical Research 16, 165177.Google Scholar
Ohta, Tomoko & Kimura, Motoo (1971). Behavior of neutral mutants influenced by associated overdominant loci in finite populations. Genetics 69, 247260.Google Scholar
Sved, J. A. (1968). The stability of linked systems of loci with a small population size. Genetics 59, 543563.Google Scholar
Weir, B. S. & Cockerham, C. Clark (1973). Mixed self and random mating at two loci. Genetical Research 21, 247262.Google Scholar