Diversity and functional roles of yeasts in fungus-growing insects

Abstract

Many yeasts live in association with insects, playing a role in detoxification and chemical signaling, protection against antagonists and, eventually, in larval development. Several studies revealed the large amount of yeasts in fungus-growing insects, which are considered biological models to study insect-fungus symbioses. Nevertheless, the diversity of yeast in these systems is still poorly addressed. The present project aims at describing the diversity of yeasts and dimorphic fungi in fungus-growing insects. Attine ants (Hymenoptera: Myrmicinae: Attina) and ambrosia beetles (Coleoptera: Curculionidae: Platypodinae) will be used as study models. Moreover, yeasts will be evaluated for Killer toxin production. Such toxins play a role in fungal communities, by interference competition towards sensitive strains, and can elucidate the identification of predominant microbes in this environment. Symbiotic fungi associated with beetles (Ophiostomatales, Microascales, and occasionally Hypocreales: Fusarium) will be evaluated for gene polymorphisms that encode for plant polymer-degrading enzymes. Such analyses may reveal selective pressures that tighten the symbioses between beetles and fungi. Therefore, the study will generate a descriptive profile in yeast community of fungus-growing insects. Additionally, it will reveal the occurrence of killer yeasts in such environments and the gene polymorphism associated with the beetles-fungus symbiosis. (AU)