Hostname: page-component-77c89778f8-m42fx Total loading time: 0 Render date: 2024-07-18T04:13:18.686Z Has data issue: false hasContentIssue false
  • English
  • Français

Transposable elements in natural populations with a mixture of selected and neutral insertion sites

Published online by Cambridge University Press:  14 April 2009

Brian Charlesworth
Brian Charlesworth
Affiliation:
Department of Ecology and Evolution, The University of Chicago, 1103 E. 57th St., Chicago, IL 60637, USA

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.

This paper examines models of the population dynamics of transposable elements when chromosomal sites vary with respect to the effect on fitness of mutations caused by element insertions. Element abundance is assumed to be stabilised solely by the joint results of transposition, excision, and selection against insertional mutations. When there are only two classes of site, selected and neutral, it is hard to find parameter values for which numbers of elements are maintained that match the findings from surveys of Drosophila populations, as elements tend to accumulate at high frequencies at the neutral sites. It is similarly hard to produce realistic equilibria with three classes of site (strongly selected, weakly selected, and neutral), when elements can transpose out of the neutral sites. If transposition from neutral sites is impossible, as might be the case for elements inserted into centric heterochromatin, then realistic equilibria can be generated if there is very weak selection against elements inserted into the majority of non-neutral sites. This model predicts a modest over-representation of elements at the neutral sites. It also predicts that elements should be under-represented on the X chromosome compared with the autosomes, but this is not generally found to be the case. It is concluded that selection against insertional mutations is unlikely to be the major factor involved in the containment of element abundance.

Type
Research Article
Information
Genetics Research , Volume 57 , Issue 2 , April 1991 , pp. 127 - 134
Copyright
Copyright © Cambridge University Press 1991

References

Berg, D. E. & Howe, M. M. (1989). Mobile DNA. Washington, D.C.: American Society of Microbiology.Google Scholar
Charlesworth, B. (1985). The population genetics of transposable elements. In Population Genetics and Molecular Evolution(ed. Ohta, T. & Aoki, K.), pp. 213–232. Berlin: Springer Verlag.Google Scholar
Charlesworth, B. (1990). Mutation-selection balance and the evolutionary advantage of sex and recombination. Genetical Research 55, 199–222.Google Scholar
Charlesworth, B. & Charlesworth, D. (1983). Population dynamics of transposable elements. Genetical Research 42, 1–27.Google Scholar
Charlesworth, B. & Langley, C. H. (1989). The population genetics of Drosophila transposable elements. Annual Review of Genetics 23, 251–287.CrossRefGoogle ScholarPubMed
Cooley, L., Kelley, R. & Spradling, A. (1988). Insertional mutagenesis of the Drosophila genome with single P elements. Science 239, 1121–1128.CrossRefGoogle ScholarPubMed
Crow, J. F. (1970). Genetic loads and the cost of natural selection. In Mathematical Topics in Population Genetics (ed. Kojima, K.), pp. 128–177. Berlin: Springer-Verlag.Google Scholar
Crow, J. F. & Simmons, M. J. (1983). The mutation load in Drosophila. In The Genetics and Biology of Drosophila (ed. Carson, H. L., Ashburner, M. and Thomson, J. N.), pp. 1–35. London: Academic Press.Google Scholar
Eanes, W. F., Wesley, C., Hey, J. & Houle, D. (1988). The fitness consequences of P element insertion in Drosophila melanogaster. Genetical Research 52, 17–26.Google Scholar
Finnegan, D. J. & Fawcett, D. H. (1986). Transposable elements in Drosophila melanogaster. Oxford Surveys on Eukaryote Genes 3, 1–62.Google ScholarPubMed
Goldberg, S. (1961). Introduction to Difference Equations. New York: John WileyGoogle Scholar
Hilliker, A. J., Appels, R. & Schalet, A. (1980). The genetic analysis of D. melanogaster heterochromatin. Cell 21, 607–619.CrossRefGoogle ScholarPubMed
Langley, C. H., Montgomery, E. A., Hudson, R. H., Kaplan, N. L. & Charlesworth, B. (1988). On the role of unequal exchange in the containment of transposable element copy number Genetical Research 52, 223–235.Google Scholar
Montgomery, E. A., Charlesworth, B. & Langley, C. H. (1987). A test for the role of natural selection in the stabilization of transposable element copy number in a population of Drosophila melanogaster. Genetical Research 49, 31–41.Google Scholar
Mukai, T. (1969). The genetic structure of natural populations of Drosophila melanogaster. VII. Synergistic interactions of spontaneous mutant polygenes affecting viability. Genetics 61, 749–761.Google Scholar
Schmid, C. W. & Shen, C.-K. J. (1985). The evolution of interspersed repetitive DNA sequences in mammals and other vertebrates. In Molecular Evolutionary Genetics (ed. Maclntyre, R. J.), pp. 1–94. London: Academic Press.Google Scholar