Reproductive strategies and adaptations for survival among obligatory microsporidian and fungal parasites of mosquitoes: a comparative analysis of Amblyospora and Coelomomyces

Abstract

Amblyospora (Microsporida: Amblyosporidae) and Coelomomyces (Chytridiomycetes: Blastocladiales) have independently evolved a diverse array of unique and highly specialized mechanisms that have allowed them to more fully exploit their mosquito hosts and the aquatic environment that their hosts inhabit. Amblyospora and Coelomomyces both have complex life cycles that include obligatory development in an intermediate microcrustacean host and 2 mosquito generations for completion. Amblyospora is polymorphic with 3 separate and distinct developmental sequences, asexual and sexual reproduction, and aspects of both vertical (transovarial) and horizontal transmission. Infective stages of Coelomomyces are motile, a temporal gating mechanism coordinates gamete release, and, even though there is no transovarial transmission, infection of primary host ovaries is important in dissemination of the fungus to new habitats. The intent of this review is to examine how these and other strategies and adaptations facilitate parasite reproduction within the host(s) and enhance transmission and survival between hosts.