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Accueil du site > Séminaires > Archives > Année 2012 > Massimo Vergassola

Bacterial chemotaxis

Massimo Vergassola

à 11h en salle C. Brot

Bacteria respond to chemical cues by performing a biased random walk that enables them to migrate towards attractants and away from repellents. Bias is achieved by regulating the duration of the bacterial runs as a function of the environment, inferred from the history of chemoattractant detections experienced by the bacterium. This time-signal is processed using a time convolution function that can be assayed measuring the impulse response of the bacterium (to short pulses of chemoattractant). The convolution constitutes an elementary form of memory, which is encoded at the molecular level in the chemotaxis signal transduction network. While the latter is being characterized in detail, the functional reasons shaping the bacterial chemotactic response are largely unknown. We shall review the phenomenology of chemotaxis, present a novel experimental inference method to measure the chemotaxis response and discuss functional reasons driving its evolution.