Extracellular Structure-Constructing System Acquired by Unicellular Organisms

Abstract

Just as humans build houses, some unicellular organisms also construct structures outside their bodies. In testate amoebae, the mother cell constructs a shell for the daughter cell in the extracellular, template-free space before cell division. During the process of shell construction, testate amoebae show surprisingly complex behavior. How do unicellular organisms without eyes, hands, or brains construct a shell outside the cell? In this review, we introduce recent findings on the process of shell construction and the shell structure of the testate amoeba Paulinell micropora.