Collaborative Research: MIP: How Responsive are Bacterial Endosymbionts to Physiological and Eological Variation in Their Ant Hosts?

Marine Biological Laboratory, Woods Hole MA

Investigators

Abstract

Numerous organisms require vital nutrients provided by beneficial bacteria to live, grow and reproduce. Many insects are hosts to specialized bacteria that live only inside host cells and provide essential functions. Our current understanding of these functions comes primarily from the sequenced genomes of bacteria. We know what genes the bacteria have but we know very little about how and when they are used. In this study, a mutually beneficial symbiosis between Blochmannia bacteria and Camponotus ants will be used to examine dynamic interactions between bacteria and their insect hosts and to learn if bacteria are flexible enough to respond to ant needs under different conditions. Camponotus, with over 1,000 species worldwide, offer a wide variety of diets and natural environments. Also, Camponotus, like other ants, have different types of adults, or castes (e.g., queens and workers) and different developmental stages (larva, pupa, adult). This project will address the question, are Blochmannia capable of adjusting their contributions to changing and differing needs of their hosts? The PIs will compare bacterial gene expression patterns and cell densities across hosts that include distinct ant species, developmental stages, and castes, in order to clarify links between microbial functions and host physiology. Through experiments eliminating bacteria from hosts, the PIs will also explore the roles bacteria play in host development and the establishment of new ant colonies. The wide distribution and significance of mutualistic interactions with bacterial symbionts have only been appreciated relatively recently. This collaborative effort combines expertise in comparative and functional genomics, host-symbiont interactions, and insect nutritional physiology and ecology. The project interconnects these disciplines to explore associations between microbes and animals in the natural environment. This project will advance the bacterial-ant symbiosis as a new model system and will develop novel experimental approaches to study specific functions of ecologically important bacteria that grow only within hosts. Results of this work will shed light on how microbes respond to the dynamic environment of animal hosts and the various processes that shape host-symbiont coevolution. This basic research will be used as a platform for curriculum development, education spanning grade school to professional training, and community outreach.