Speaker
Description
The microbial ecosystem is full of narrow constrictions that microorganisms need to learn to navigate in order to survive. Here, we study a Nature example of a "microorganism billiard": a system composed of a population of microorganisms packed in a closed space, with only a few narrow apertures to escape from. This situation occurs when the marine parasite Parvilucifera sinerae infects and replicates inside a dinoflagellate host, and the newly born parasites find themselves in the closed and extremely packed space represented by the dead host body (the "sporangium"). In order to start a new successful infection cycle, the parasite's zoospores must find their way out of this closed structure. Which strategies are deployed by the parasites to manage a successful escape? A particular interaction with the boundaries might help them navigate this structure, and collective behaviours between individual parasites might be key in "finding the way out". To understand this phenomenon, we borrow the mathematical formulation of the "active billards", a biological reformulation of the "billard theory" first developed in dynamical systems, and try to extract information about what is happening inside the sporangium from the zoospores escape dynamics. We present the preliminary results of our experiments aimed at characterizing the exit dynamics using high-magnification cameras. Additionally, we introduce the design of a microfluidic chip that facilitates the study of chemoresponses of swimming zoospores to chemical cues.
