GELIFES Seminars - Beatriz Vicoso

Beatriz Vicoso (IST Austria)

Gene expression evolution in sexual and asexual species of Artemia brine shrimp

Sexual and asexual populations have fundamentally different evolutionary dynamics. Asexual populations are thought to be under inefficient selection, and often become rapidly extinct. Sexual species can in theory adapt more easily, but are constrained by the fact that a single genome is under selection in both males and females. If the fitness optima differ between them, this can prevent either sex from reaching their own optimum, leading to a so called "gender load". We are investigating patterns of gene expression in sexual and asexual populations of brine shrimp of the genus Artemia to test these predictions. If there is a significant gender load in the sexual species, asexual females, which are released from this constraint, should invest more in female functions. The opposite is expected if reduced selection efficacy in asexual populations is the dominant factor at play. We are also using Artemia as a model for understanding the evolution of ZW chromosomes, a type of sex chromosomes that have been traditionally less studied than XY chromosomes, in part due to the lack of model ZW systems easily amenable to experiments.