EPFL BioE Talks SERIES "Hydrodynamic Flow and Concentration Gradients in the Gut Enhance Neutral Bacterial Diversity"


Event details

Date 17.05.2021 16:3017:00  
Speaker Prof. Anne-Florence Bitbol, Institute of Bioengineering, EPFL, Lausanne (CH)
Location Online
Category Conferences - Seminars

(note that this talk is number two of a double-feature seminar - see details of the first talk here)

The gut microbiota features important genetic diversity, and the specific spatial features of the gut may shape evolution within this environment.
We investigate the fixation probability of neutral bacterial mutants within a minimal model of the gut that includes hydrodynamic flow and resulting gradients of food and bacterial concentrations. We find that this fixation probability is substantially increased compared to an equivalent well-mixed system, in the regime where the profiles of food and bacterial concentration are strongly spatially-dependent. Fixation probability then becomes independent of total population size. We show that our results can be rationalized by introducing an active population, which consists of those bacteria that are actively consuming food and dividing. The active population size yields an effective population size for neutral mutant fixation probability in the gut.

Anne-Florence Bitbol studied physics at ENS Lyon (F). Her PhD at Université Paris-Diderot, advised by Prof. Jean-Baptiste Fournier, focused on the statistics and dynamics of complex membranes, using statistical and soft matter physics to understand how lipid bilayers are perturbed by proteins or by local chemical perturbations. She then chose to move even closer to biology, as a postdoc in the Biophysics Theory Group at Princeton University, led by Profs. Ned Wingreen, Bill Bialek and Curt Callan. There, she investigated the self-assembly of multi-protein complexes, and she also worked on evolution in rugged fitness landscapes with David Schwab. Next, she became a CNRS researcher at Laboratoire Jean Perrin, Institut de Biologie Paris-Seine, Sorbonne Université in Paris, before moving to EPFL, where she is a Tenure-Track Assistant Professor in the Institute of Bioengineering and the School of Life Sciences. She is broadly interested in understanding biological phenomena in a quantitative way, through physical concepts as well as mathematical and computational tools. Her current research focuses on two main axes: the sequence-function mapping in proteins, and the evolution of microbes on complex fitness landscapes and in complex environments.

Zoom link (with registration) for attending remotely: https://go.epfl.ch/EPFLBioETalks

IMPORTANT NOTICE: due to restrictions resulting from the ongoing Covid-19 pandemic, this seminar can be followed via Zoom web-streaming only, (following prior one-time registration through the link above).

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