Berlin 2024 – scientific programme

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BP: Fachverband Biologische Physik

BP 6: Bacterial Biophysics I

BP 6.3: Talk

Monday, March 18, 2024, 15:45–16:00, H 1028

Genealogical organization in growing bacterial colonies — Garima Rani¹ and •Anupam Sengupta^1,2 — ¹Physics of Living Matter Group, Department of Physics and Materials Science, University of Luxembourg — ²Institute for Advanced Studies, University of Luxembourg

Spatio-temporal organization of individuals within growing bacterial colonies is a key determinant of intraspecific interactions and colony-scale heterogeneities. The evolving cellular distribution, in relation to the genealogical lineage, is thus central to our understanding of bacterial fate across scales. Yet, how bacteria self-organize genealogically as a colony expands has remained unknown. In this work we report recent results obtained using a custom-built label-free algorithm to track bacterial genealogy in growing colonies. Our results reveal emergence of distinct self-similar genealogical enclaves, whose dynamics are governed by biological activity. The enclaves boundaries are populated by topological defects, which tune finger-like morphologies of the active interfaces. Estimation of the Shannon entropy of cell arrangements show a reduction over time; with faster dividing cells possessing higher spatial affinity to genealogical relatives, at the cost of a well-mixed, entropically favorable state. We complement the experimental results with a coarse-grained lattice model, demonstrating that the genealogical enclaves emerge due to an interplay of division-mediated dispersal, stochasticity of division events, and cell-cell interactions. Our study reports so-far hidden emergent self-organizing features which modulate genealogical distances within growing bacterial colonies.

Keywords: genealogy; self-organization; Shannon entropy; active interfaces; topological defects