Annals of Botany Lecture - Dr. Loren Rieseberg
Rieseberg, Loren H. .
Speciation Genes in Plants.
Identification and characterization of the genes that cause reproductive isolation has proven to be a powerful method for understanding how species arise. Unfortunately, most compilations and discussions of “speciation genes” have focused on a handful of genes that contribute to intrinsic postzygotic isolation in animals, mainly Drosophila. Here I redress this imbalance by compiling a list of more than a dozen genes that contribute to prezygotic or postzygotic isolation in plants. Analyses of the molecular evolution of these genes supports conclusions from the zoological literature: reproductive isolation often arises as a byproduct of positive selection, and genetic conflict and sexual selection likely play an important role in speciation in both plants and animals. There are several apparent differences as well. Resistance genes appear to contribute importantly to the evolution of hybrid inviability in plants, but there is little evidence for such a role in animals. Likewise, cytoplasmic male sterility is frequently detected in plant hybrids, but it appears to be rare in animals. A final apparent difference between plants and animals (or at least Drosophila) is that most gene incompatibilities characterized in plants appear to be polymorphic within species. This may be due to ascertainment bias, dissimilar levels of intraspecific gene flow, and/or differences in the evolutionary forces that gave rise to the incompatibilities in the first place.
Log in to add this item to your schedule
1 - University of British Columbia, Department of Botany, 3529-6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada
Presentation Type: Special Presentation
Date: Tuesday, July 29th, 2008
Time: 10:00 AM