GEE Friday Seminar Series - Jasmine Ono - 16 February 2018
Feb 16, 2018 01:00 PM
End: Feb 16, 2018 02:00 PM
Title: Genetics of adaptation in experimental populations of yeast
Speaker: Jasmine Ono, Dr Duncan Greig lab
Venue: G02 Watson LT, Medawar Building (map)
Abstract: Evolution proceeds through genetic changes to individuals, which are either propagated or disappear over generations. Adaptation is one of the main mechanisms driving these changes in genetic composition. Speciation can also result from different, and incompatible, genetic changes occurring in different populations. I have investigated the genetics of adaptation and speciation using laboratory populations of the budding yeast Saccharomyces cerevisiae. I have found that the environment can strongly influence both the number of genes that are the targets of selection and the types of potentially beneficial mutations, having implications for the repeatability of evolution. I have also found that ploidy level of the organism can strongly influence their ability to adapt, affecting their likelihood of undergoing evolutionary rescue. Finally, I have found that individually isolated single-step beneficial mutations from the same selective environment can have negative genetic interactions, of the type that underlies speciation. These interactions became positive, however, when the level of stress was increased, indicating that genetically-based reproductive isolation can also be environment-dependent. Together, these results have implications for our understanding of the genetic basis of adaptation in different types of environments and different levels of the same environmental stressor.