Meeting Abstract

12.6  Saturday, Jan. 4 11:30  Estimating the Frequency of Sex in Symbiodinium WHAM, DC*; LAJEUNESSE, TC; Penn State; Penn State wham@psu.edu

The amount of sexual recombination in the genealogy of partially clonal organisms can be highly variable. This rate, however, can have a large effect on the tempo and mode of evolution in these organisms. The process of sexual recombination facilitates the combination and spread of favourable mutations, rapidly creating new genotypic variability. Alternatively, clonal reproduction allows for the rapid proliferation of successful genotypes allowing for genetic stability over multiple loci without the need for physical linkage. Here we apply a method based on coalescent theory to estimate the population sexual reproduction rate, 4NeSe, from multi-locus genetic data from the symbionts of reef-building corals. Our results suggest that rates of sexual reproduction are highly variable within and between the examined taxa. We suggest that the mode of symbiont acquisition plays a primary role in driving the rate of sexual reproduction in Symbiodinium.