ECIMMEE Project: Patterns of Specificity and Maintenance in Microbe-Microbe partnerships
Microbe-microbe symbioses are ubiquitous across many marine habitats and participate in fundamental ecosystem processes via the transformation of energy and matter. Many of these partnerships are obligate and, consequently, must be maintained across generations, either by continuing their partnership through cell division or through reacquisition of their symbiont from the environment by each new generation. Compared to what is known about symbiont fidelity and intergenerational transmission in symbiotic, multicellular hosts like plants and animals, there is a large gap in knowledge regarding these processes in partnerships between unicellular organisms. We will investigate partner specificity and transmission dynamics in anaerobic ciliates and their prokaryotic partners, which are conspicuously abundant microbe-microbe symbioses commonly found in anoxic and oxygen-depleted marine ecosystems. Specifically, we will investigate patterns of specificity and maintenance dynamics in multipartner consortia consisting of anaerobic ciliates from the classes Armophorea or Plagiopylea, intracellular endosymbiotic methanogenic archaea, and/or surface-associated episymbiotic sulfate-reducing bacteria. This project will: 1) use phylogenetic and phylogenomic analysis to understand patterns of partner codiversification; 2) utilize field assessment and laboratory experiments to investigate partner specificity and patterns of transmission (that is, vertical vs. horizontal); and 3) deploy genetic/genomic analyses and microscopy to characterize the prokaryotic symbiont population structure associated with characterized maintenance strategy. Given the importance of microbe-microbe symbioses to marine ecosystems, increased knowledge of partner specificity and transmission is critical to our understanding of the persistence of these partnerships and their effect on the ecology and evolution of marine microbes.
Roxanne Beinart is an assistant professor at the University of Rhode Island’s Graduate School of Oceanography. Her laboratory studies the effects of marine microbial symbioses on ecosystem-level processes using an integrative approach that brings together insights from physiological experiments, molecular-based ’omics tools, physicochemical measurements, and community surveys. Research in the Beinart Lab describes the mechanistic links among symbiont physiology, ecological processes, and biogeochemical cycles, with the ultimate goal of advancing knowledge of the function and significance of microbes in marine ecosystems. Beinart received a B.S. in biology from Cornell University in 2006 and a Ph.D. in biology from Harvard University in 2014. Before coming to URI, she carried out postdoctoral research at the Woods Hole Oceanographic Institution as a National Science Foundation Ocean Sciences Postdoctoral Fellow and a WHOI Coastal Ocean Institute Scholar.