Long-term Sabbatical

The evolutionary ecology of genetic conflict in plants

PI(s): Christina M Caruso (University of Guelph (CANADA))
Start Date: 1-Sep-2011
End Date: 31-May-2012
Keywords: ecology, species interactions, natural populations, mating systems, selfish genes

A key feature of eukaryotes is that they have both cytoplasmic and nuclear genomes. While compatibility between these genomes is necessary for eukaryotes to function, there can also be ongoing intergenomic conflict. Such conflict is thought to play a significant role in the evolution of the genes that underlie hybrid incompatibility and thus speciation. For my sabbatical research, I will focus on the most common type of intergenomic conflict in plants, between cytoplasmic male sterility (CMS) genes that disrupt pollen production and nuclear genes that restore pollen production (Rf). Conflict between CMS and Rf can be resolved in two ways. In most species, Rf alleles go to fixation, resulting in hermaphroditism. In a minority of angiosperms, Rf alleles do not go to fixation, resulting in gynodioecy, a breeding system where plants produce either female flowers or hermaphrodite flowers. Most explanations for why Rf alleles do or do not go to fixation have focused on the genetics of male fertility restoration. In contrast, the ecology of restoration remains virtually unexplored. By synthesizing concepts from four different fields--breeding system evolution, phenotypic plasticity, pollination ecology, and herbivore defense--I will develop hypotheses about the role of ecology in determining the frequency of Rf alleles, and then use a phylogenetic analysis of correlated evolution to test predictions from one of my hypotheses. This work will have implications for the evolution of gender dimorphism in plants, as well as the potential for CMS/Rf to function as speciation genes.

Related products

Software and Datasets
  • Caruso CM, Case A (2012) Data from: Testing models of sex ratio evolution in a gynodioecious plant: female frequency covaries with the cost of male fertility restoration. Dryad Digital Repository. doi:10.5061/dryad.v5n09
Publications
  • Testing models of sex ratio evolution in a gynodioecious plant: female frequency covaries with the cost of male fertility restoration. Caruso, C. M. and A. L. Case. 2013. Testing models of sex ratio evolution in a gynodioecious plant: female frequency covaries with the cost of male fertility restoration. Evolution 67:561-566.
  • Sexual dimorphism in floral traits of gynodioecious Lobelia siphilitica L. (Lobeliaceae) is consistent across populations. Caruso, C.M. Sexual dimorphism in floral traits of gynodioecious Lobelia siphilitica L. (Lobeliaceae) is consistent across populations. Botany 90: 1245-1251.
  • The evolutionary ecology of cytonuclear interactions in angiosperms Caruso, C. M., A. L. Case, and M. F. Bailey. 2012. The evolutionary ecology of cytonuclear interactions in angiosperms. Trends in Plant Science 17:638-643.
Presentations
  • Bailey, M. F., C. M. Caruso, and A. L. Case. 2012. Ecological effects on male fertility restoration in cytonuclear gynodioecy. Oral presentation. First Joint Congress on Evolutionary Biology, Ottawa, ON, Canada.
  • Case, A. L. and C. M. Caruso. 2012. Testing models of sex ratio evolution in a gynodioecious plant. Oral presentation. First Joint Congress on Evolutionary Biology, Ottawa, ON, Canada.
  • Caruso, C. M. July 3 2012. The evolutionary ecology of cytonuclear interactions in flowering plants. Mountain Lake Biological Station, University of Virginia.
  • Caruso, C. M. February 10 2012. The evolutionary ecology of cytonuclear interactions in flowering plants. Department of Biology Lunch Bunch, University of North Carolina.
  • Caruso, C. M. October 27 2011. The evolutionary ecology of cytonuclear interactions in flowering plants. Department of Biology, East Carolina University.
  • Caruso, C. M. November 21 2011. The evolutionary ecology of cytonuclear interactions in flowering plants. Department of Biology, College of Charleston.
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