David Lacoste

Research·02 / 06

Fluctuations and growth in cell populations

Even in a constant environment, genetically identical cells grow and divide at different rates. I study how this variability shapes the growth of a population, its response to drugs, and its strategies to cope with a changing world.

Antibiotics · Lineage trees · Bet hedging

Lineages and populations

A growing population can be observed either by following single lineages or by taking snapshots of the whole population, and the two views give different statistics. We derived fluctuation relations that link them, obtained universal constraints on the strength of selection in lineage trees, and developed methods that work with the incomplete trees recorded in real experiments.

Bacteria and antibiotics

Small bacterial populations exposed to antibiotics can either recover or go extinct. We model how the drug inhibits growth, and showed that the interplay between stochastic division and death leads to a bistable growth regime in small populations.

Growth in an uncertain environment

When the environment fluctuates, a population can hedge its bets by switching between phenotypes. Using analogies with optimal betting, we identified phase transitions in optimal strategies and the Pareto-optimal trade-offs between growth and its fluctuations.

Publications 9

All publications

Susceptibility of bacteria to antibiotics

Variability in growth and division

Adaptation to an uncertain environment