Holly Elmore, Graduate Student
Haig Lab, Department of Organismic and Evolutionary Biology
Topic: Investigating patterns of HD1 and HD2 mating gene diversity through space and time: insights on how mating system influences invasion and vice versa in Amanita phalloides.
Amanita phalloides, the Death Cap, is an ectomycorrhizal fungus native to Europe and invasive in California (CA), introduced in the last century. Like other Basidiomycotans, A. phalloides has a two-locus, tetrapolar mating system, in which mates must have different alleles at both of the loci, i.e. have different mating types. Diversity at these loci is typically extremely high, and many Basidiomycotan species have thousands of mating types. This is believed to be due to negative frequency-dependent selection of novel alleles. Presumably, diversity at mating type alleles was bottlenecked during the introduction of A. phalloides to CA.
Here, I examine of alleles of the genes HD1 and HD2, the core self-incompatibility genes of the HD (or A) mating locus, sequenced from 86 A. phalloides individuals collected in mapped populations from the invasive range in California as well as across the native range in Europe, with mapped populations from Portugal. The California samples include survey populations that were collected from in 2005, 2014, and 2015, allowing to take a history of HD mating locus diversity through both time and space. These data have the potential to elucidate both the evolution of mating types in tetrapolar systems and how the effects of bottlenecking and invasion on the mating system in turn affect the distribution of genetic diversity throughout the population.