Abstract
Two two-locus models of the population dynamics of the segregation distortion (SD) polymorphism of Drosophila melanogaster are described. One model is appropriate for understanding the population genetics of SD in nature, whereas the other is a special case appropriate for understanding an artificial population that has been extensively analysed. The models incorporate the general features of the Sd and Rsp loci which form the core of the SD system. It is shown that the SD polymorphism can be established only when there is sufficiently tight linkage between Sd and Rsp. An approximate treatment, valid for tight linkage, is given of all the equilibria of the system and their stabilities. It is shown that the observed composition of natural and artificial populations with respect to the Sd and Rsp loci is predicted well by the model, provided that restrictions are imposed on the fertilities of certain genotypes. Highly oscillatory paths towards equilibrium are usually to be expected on the basis of this model. The selection pressures on inversions introduced into this system are also investigated.
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Selected References
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- Hartl D. L. Dysfunctional sperm production in Drosophila melanogaster males homozygous for the segregation distorter elements. Proc Natl Acad Sci U S A. 1969 Jul;63(3):782–789. doi: 10.1073/pnas.63.3.782. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miklos G. L. An investigation of the components of Segregation-Distorter systems in Drosophila melanogaster. Genetics. 1972 Mar;70(3):405–418. doi: 10.1093/genetics/70.3.405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nei M. Modification of linkage intensity by natural selection. Genetics. 1967 Nov;57(3):625–641. doi: 10.1093/genetics/57.3.625. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tokuyasu K. T., Peacock W. J., Hardy R. W. Dynamics of spermiogenesis in Drosophila melanogaster. VII. Effects of segregation distorter (SD) chromosome. J Ultrastruct Res. 1977 Jan;58(1):96–107. doi: 10.1016/s0022-5320(77)80011-7. [DOI] [PubMed] [Google Scholar]
- Trippa G., Loverre A. A factor on a wild third chromosome (IIIRa) that modifies the segregation distortion phenomenon in Drosophila melanogaster. Genet Res. 1975 Oct;26(2):113–125. doi: 10.1017/s0016672300015925. [DOI] [PubMed] [Google Scholar]