Obligate, intracellular bacteria of the genus Wolbachia often behave as reproductive parasites by manipulating host reproduction to enhance their vertical transmission. One of these reproductive manipulations, cytoplasmic incompatibility, causes a reduction in egg hatch rate in crosses between individuals with differing infections. Wolbachia superinfection in the mosquito Aedes albopictus is associated with both cytoplasmic incompatibility and increased host fecundity. Relative to uninfected females, infected females live longer, produce more eggs, and have higher hatching rates in compatible crosses. A model describing Wolbachia infection dynamics predicts that increased fecundity will accelerate cytoplasmic drive rates. To test this hypothesis, we used population cages to examine the rate at which Wolbachia invades an uninfected A. albopictus population. The observed cytoplasmic drive rates were consistent with model predictions for a CI-inducing Wolbachia infection that increases host fecundity. I will discuss the relevance of these results to the evolution of Wolbachia symbioses. A general model that describes the interaction between Wolbachia infection frequency and host population size will also be discussed in relation to natural invasions of Wolbachia infections and artificial releases of infected hosts.
Species 1: Diptera Culicidae Aedes albopictus (Asian Tiger Mosquito)
Keywords: cytoplasmic incompatibility, evolution
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