CAREER: Establishing the Drosophila proventriculus as a model symbiosis organ

Carnegie Institution Of Washington, Washington DC

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Most animals maintain certain types of bacteria in their gut that aid the animal by improving the nutrition of the diet and modulating the immune system. Microbial associations are particularly important in insects, which are critically important to agriculture, ecology, and human health, including pollinators such as bees, pests such as squash bugs and fruit flies, and disease vectors such as mosquitos and ticks. How insects recruit and maintain their preferred bacteria is largely unknown in terms of the specific genes and molecules the host uses to regulate colonization. The proposed research aims to close this knowledge gap by identifying these genes and molecules and how specific host cells regulate them. Due to critical roles of insects in ecology, agriculture, and public health, outcomes of the proposed research could have major impacts by developing uses of symbiotic bacteria to aid and control insects. Furthermore, the high conservation of gene function across mammals means discoveries in insects could apply to other animals, including vertebrates. Broader impacts of this grant also include development and implementation of hands-on and online microbiology curricula in public schools. Across animals, there is a knowledge gap around the precise developmental genetic mechanisms that construct and maintain the host tissues that house symbiotic organisms as well as whether a host can use certain bacteria to control others. Drosophila has long been a workhorse of animal developmental genetics, with unparalleled resources of publicly available genetic stocks with defined gene perturbations, and the wide genetic conservation across the animal kingdom. The PI’s discovery of symbiotic bacteria that form an adherent, multispecies community in a precise and understudied section of the Drosophila foregut presents a transformative opportunity to apply Drosophila genetics to the study of symbiosis between diverse gut bacteria and the host. This research will define the Drosophila symbiotic organ in terms of the fly genes that support the bacteria. Host genetic pathways, in secretion and immunity will be evaluated by quantitative cell biology, microbiology, and genomics approaches as well as by isotope ratio mass spectrometry, which will be used to measure nutrient exchange between host and bacteria. This will advance the field by providing candidate genes and developmental programs to discover symbiotic niches in other insects and animals, possibly even humans. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.