Dr. David Booth
Assistant Professor, UCSF School of Medicine, Biochemistry and Biophysics
Lab Website

Choanoflagellates as models to investigate the evolution of intercellular cooperation

Tuesday, October 29
11:30 AM
AHF 153 (Torrey Webb Room)

Abstract: My lab studies how intercellular interactions evolve to support the physiology of multicellular organisms and to mediate interaction in microeukaryotic communities. Our current work focuses on a key group of marine microeukaryotes, the choanoflagellates, to determine how they transform themselves into distinct types of cells that can inhabit different ecosystems comprised of microeukaryotes. We suspect that the mechanisms choanoflagellates deploy for cell specialization, resource sharing, and interspecies communication in microeukaryotic communities evolved from a genetic toolkit that also laid the foundation for the multicellular physiology of animals–the closest living relatives of choanoflagellates. In this talk, I will share our recent research showing that cell differentiation in the model choanoflagellate Salpingoeca rosetta controls the assimilation of iron from colloidal particles. As other phagotrophic microeukaryotes can alleviate iron limitation for phytoplankton and bacteria by digesting iron colloids, we hypothesize that choanoflagellates share essential nutrients with organisms in their surrounding environment.  To investigate this hypothesis, we have reconstituted microbial communities in the laboratory and isolated communities from the wild to characterize how choanoflagellates associate with algae, which has led to discover that an algal polysaccharide triggers multicellular development in Salpingoeca rosetta. This interaction opens a new opportunity to determine how epiphytic microeukaryotes support the ecological functions of marine algae.