Inducing factors for encystment and excystment in ciliated protozoan Colpoda sp.

Abstract

In many kinds of protozoans, cyst formation (encystment) and excystment which involves structural transformation processes constitute the drastic process of cell reconstruction mediated by signaling chains including gene expression that is triggered by environmental signals. In order to establish a model system for understanding the molecular mechanisms of encystment and excystment, we aimed to elucidate the environmental factors that activate the signal transduction chain leading to encystment and excystment of Colpoda sp. The present study showed that cyst formation of Colpoda was repressed by bacteria, while accelerated by saline solution. The excystment of the cells was induced by certain components contained in dried cereal leaves.