NSF Postdoctoral Fellowship in Biology FY 2019: Coevolutionary genomics of a dual-purpose marine symbiosis

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2019, Broadening Participation of Groups Under-represented in Biology. The fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. Coevolution between animals and the microorganisms they live with (microbial symbionts) often results in changes such as novel molecules, that can protect the host organism. If the microbial symbionts are passed from parent to offspring it is usually an advantage when the environment stays the same. In contrast, marine ecosystems, which often experience change, may provide an advantage to organisms that acquire their microbial symbionts from the environment. This project will analyze the interaction of a marine crustacean called an isopod with microbes called cyanobacteria. The research will use this model system of marine symbioses to test evolutionary theories about how organisms coevolve. The fellow will simultaneously develop a bridge program focused on providing marine science research opportunities to underrepresented community college students, thus giving students training unavailable at their home institutions. In doing so, the project will provide training in population genomics, meta-genomics, and scientific diving.<br/><br/>Reef-dwelling isopods (Santia) cultivate dual-purpose, cyanobacteria - these symbionts are the isopod's primary food source and provide defense from predation. Defense is conferred via conspicuous warning coloration and compounds that are unpalatable to predatory fishes. Theory predicts these symbionts should be a diverse and undifferentiated microbial assemblage, consistent with the 'Everything is Everywhere' hypothesis. However, Santia brood their young, which should favor vertical transmission and co-diversification. This research will use microbial community profiling to determine whether symbiont benefits derive from a consortium of microbial species or a single specialized lineage. Symbiont transmission will be determined by comparing isopod geographic population structure against spatial patterns of symbiont genetic population and community structure. Isopod and symbiont co-divergence will be examined using comparative phylo-genomics with an isopod-symbiont system lacking defensive compounds and pigment. The fellow will create a 'Marine Science Pathways (MSP)' program that will act as a feeder to 'The Diversity Project' a research-intensive international summer program focused on increasing diversity in marine science by providing a pathway to PhD programs. MSP will recruit underrepresented students from community colleges to conduct research and participate in a journal club where PhD students who are TDP alumni will discuss science and paths to graduate school.<br/><br/>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.