Skip to main content Accessibility help
×
Home

Multilocus models of inbreeding depression with synergistic selection and partial self-fertilization

  • B. Charlesworth (a1), M. T. Morgan (a1) and D. Charlesworth (a1)

Summary

Mean fitness and inbreeding depression values in multi-locus models of the control of fitness were studied, using both a model of mutation to deleterious alleles, and a model of heterozygote advantage. Synergistic fitness interactions between loci were assumed, to find out if this more biologically plausible model altered the conclusions we obtained previously using a model of multiplicative interactions. Systems of unlinked loci were assumed. We used deterministic computer calculations, and approximations based on normal or Poisson theory. These approximations gave good agreement with the exact results for some regions of the parameter space. In the mutational model, we found that the effect of synergism was to lower the number of mutant alleles per individual, and thus to increase the mean fitness, compared with the multiplicative case. Inbreeding depression, however, was increased. Similar effects on mean fitness and inbreeding depression were found for the case of heterozygote advantage. For that model, the results were qualitatively similar to those previously obtained assuming multiplicativity. With the mutational load model, however, the mean fitness sometimes decreased, and the inbreeding depression increased, at high selfing rates, after declining as the selfing rate increased from zero. We also studied the behaviour of modifier alleles that changed the selfing rate, introduced into equilibrium populations. In general, the results were similar to those with the multiplicative model, but in some cases an ESS selfing rate, with selfing slightly below one, existed. Finally, we derive an approximate expression for the inbreeding depression in completely selfing populations. This depends only on the mutation rate and the dominance coefficient and can therefore be used to obtain estimates of the mutation rate to mildly deleterious alleles for plant species.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Multilocus models of inbreeding depression with synergistic selection and partial self-fertilization
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Multilocus models of inbreeding depression with synergistic selection and partial self-fertilization
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Multilocus models of inbreeding depression with synergistic selection and partial self-fertilization
      Available formats
      ×

Copyright

Corresponding author

Corresponding author.

References

Hide All
Abbott, R. J. & Gomes, M. F. (1988). Population genetic structure and outcrossing rate of Arabidopsis thaliana (L.) Heynh. Heredity 62, 411418.
Bondari, K. & Dunham, R. A. (1987). Effects of inbreeding on economic traits in channel catfish. Theoretical and Applied Genetics 74, 19.
Campbell, R. B. (1986). The interdependence of mating structure and inbreeding depression. Theoretical Population Biology 30, 232244.
Charlesworth, B. (1980). The cost of sex in relation to mating system. Journal of Theoretical Biology 84, 655671.
Charlesworth, B. (1990). Mutation-selection balance and the evolutionary advantage of sex and recombination. Genetical Research 55, 199221.
Charlesworth, D. & Charlesworth, B. (1987). Inbreeding depression and its evolutionary consequences. Annual Review of Ecology and Systematics 18, 237268.
Charlesworth, D. & Charlesworth, B. (1990). Inbreeding depression with heterozygote advantage and its effect on selection for modifiers changing the outcrossing rate. Evolution 44, 870888.
Charlesworth, D., Morgan, M. T. & Charlesworth, B. (1990). Inbreeding depression, genetic load and the evolution of outcrossing rates in a multi-locus system with no linkage. Evolution 44, 14691489.
Crow, J. F. (1970). Genetic loads and the cost of natural selection. In Mathematical Models in Population Genetics (ed. Kojima, K.-I.), pp. 128177. Berlin: Springer-Verlag.
Crow, J. F. & Simmons, M. J. (1983). The mutation load in Drosophila. In The Genetics and Biology of Drosophila (ed. Ashburner, M., Carson, H. L. and Thompson, J. N.), pp. 135. London: Academic Press.
Darwin, C. R. (1862). The Various Contrivances by which Orchids are Fertilised by Insects. London: John Murray.
Gallais, A. (1984). An analysis of heterosis versus inbreeding effects with an autotetraploid cross-fertilized plant: Medicago sativa. Genetics 106, 123137.
Griffin, A. R. & Lindgren, D. (1985). Effect of inbreeding on production of filled seed in Pinus radiata – experimental results and a model of gene action. Theoretical and Applied Genetics 71, 334343.
Griffing, B. (1989). Genetic analysis of plant mixtures. Genetics 122, 943956.
Griffing, B. & Langridge, J. (1963). Phenotypic stability of growth in the self-fertilized species, Arabidopsis thaliana. In Statistical Genetics and Plant Breeding (ed. Hanson, W. D. and Robinson, H. F.), pp. 368394. Washington, D.C.: NAS-NRC.
Griffing, B. & Zsiros, E. (1971). Heterosis associated with genotype-environment interactions. Genetics 68, 443455.
Heller, J. & Smith, J. M. (1979). Does Muller's ratchet work with selling? Genetical Research 32, 289293.
Holsinger, K. E. (1988). Inbreeding depression doesn't matter: the genetic basis of mating system evolution. Evolution 42, 12351244.
Hopf, F. A., Michod, R. E. & Sanderson, M. J. (1988). The effect of reproductive system on mutation load. Theoretical Population Biology 33, 243265.
Imam, A. G. & Allard, R. W. (1965). Population studies in predominantly self-pollinated species. VI. Genetic variability between and within natural populations of wild oats from differing habitats in California. Genetics 51, 4962.
Jones, D. F. (1939). Continued inbreeding in maize. Genetics 24, 462–173.
Kimura, M. & Maruyama, T. (1966). The mutational load with epistatic gene interactions in fitness. Genetics 54, 13371351.
Kimura, M. & Ohta, T. (1971). Theoretical Topics in Population Genetics. Princeton, New Jersey: Princeton University Press.
King, J. L. (1967). Continuously distributed factors affecting fitness. Genetics 53, 403413.
Knight, S. E. & Waller, D. M. (1986). Genetic consequences of outcrossing in the cleistogamous annual, Impatiens capensis. I. Population genetic structure. Evolution 41, 969978.
Kondrashov, A. S. (1985). Deleterious mutation as an evolutionary factor. II. Facultative apomixis and selfing. Genetics 111, 635653.
Kondrashov, A. S. (1988). Deleterious mutations and the evolution of sexual reproduction. Nature 336, 435440.
Lande, R. & Schemske, D. W. (1985). The evolution of self-fertilization and inbreeding depression in plants. I. Genetic models. Evolution 39, 2440.
Lynch, M. (1988). Design and analysis of experiments on random genetic drift and inbreeding depression. Genetics 120, 791807.
Nagylaki, T. (1976). A model for the evolution of self fertilization and vegetative reproduction. Journal of Theoretical Biology 58, 5558.
Riley, R. (1956). The influence of the breeding system on the genecology of Thlaspi alpestre L. New Phytologist 55, 319330.
Schmitt, J., Eccleston, J. & Ehrhardt, D. W. (1987). Density-dependent flowering phenology, outcrossing, and reproduction in Impatiens capensis. Oecologia 72, 341347.
Schmitt, J. & Ehrhardt, D. W. (1990). Effects of intraspecific competition on outcrossing advantage in Impatiens capensis. Evolution 44, 269278.
Sved, J. A., Reed, T. E. & Bodmer, W. F. (1967). The number of balanced polymorphisms that can be maintained in a natural population. Genetics 55, 469481.
Sved, J. & Wilton, A. N. (1989). Inbreeding depression and the maintenance of deleterious genes by mutation: model of a Drosophila chromosome. Genetical Research 54, 119128.
Svensson, L. (1988). Inbreeding, crossing and variation in stamen number in Scleranthus annuus (Caryophyllaceae), a selfing annual. Evolutionary Trends in Plants 2, 3139.
Waller, D. M. (1984). Differences in fitness between seedlings derived from cleistogamous and chasmogamous flowers in Impatiens capensis. Evolution 38, 427440.
Wright, S. (1977). Evolution and the Genetics of Populations, vol. 3, Experimental Results and Evolutionary Deductions. Chicago: University of Chicago Press.
Ziehe, M. & Roberds, J. H. (1989). Inbreeding depression due to overdominance in partially self-fertilizing plant populations. Genetics 121, 861868.

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed