Changes in the frequency of facultative endosymbionts in insect populations: overview and applications

Abstract

Many insect endosymbionts are facultative from the host perspective, and their population frequencies across time and space will depend on their transmission fidelity and effects on host fitness. These effects and transmission rates in turn depend on the environmental and host genetic contexts where the endosymbionts occur. Endosymbionts like Wolbachia and Cardinium affect host reproduction to produce transient or persistent presence/absence polymorphisms, while other endosymbionts like Regiella and Hamiltonella persist through providing host fitness benefits and transmitting horizontally. Evolutionary changes in hosts and endosymbionts affect these impacts and endosymbiont polymorphisms in ..