[2Ap01-12] Symposium

[2Ap12] Graviresponses of unicellular protists

*Azusa Kage¹, Yoshihiro Mogami² (1. Department of Physics, Gakushuin University, 2. Graduate School of Humanities and Sciences, Ochanomizu University)

Organisms on earth respond to gravity. Even small unicellular protists show graviresponses. Many protists tend to go against gravity, i.e. negative gravitaxis. Another gravity-related phenomenon by unicellular protists is bioconvection. Bioconvection is a self organization phenomenon induced by gravity and negative gravitaxis. When protists are abundant in the aqueous environment, regular patterns of density emerge, of which scale is 100-1000 times larger than individual protists. In this presentation, we discuss the mechanisms of negative gravitaxis in the unicellular green alga Chlamydomonas reinhardtii and responses of bioconvection to altered gravity during parabolic flights.