A novel chemotactic response can reduce viral infection in Micromonas populations

Micromonas commoda is a common motile uniflagellate pico-eukaryote found in marine environments. Previously, we have observed that the death and lysis of a single cell of Micromonas releases chemicals that triggers a novel motility response of other nearby Micromonas, in which they swim rapidly in a random direction. For the population of Micromonas surrounding a dying cell, this leads to a "burst event" in which Micromonas are locally depleted around the dying cell. It is known that viral infections are an important factor in Micromonas populations, causing up to 10% of deaths. Here, we hypothesize that burst events reduce the exposure and spread of viral infection in a Micromonas population, since dying cells release infectious viral particles. We develop a model for how a cell's motility response changes the amount of viral particles it will encounter after the lysis of a nearby cell. We find that the observed motility response can significantly reduce the exposure to viral particles.