Front Cover: Specific Spatial Localization of Actin and DNA in a Water/Water Microdroplet: Self‐Emergence of a Cell‐Like Structure (ChemBioChem 13/2018)

Abstract

The front cover picture shows selective localization of F‐actin (polymerized filament) and double‐stranded DNA within a cell‐sized aqueous/aqueous droplet that was generated spontaneously through simple mixing with binary hydrophilic polymers, poly(ethylene glycol) and dextran (DEX). Interestingly, the manner of localization of these biomacromolecules switches depending on their molecular size. Long double‐stranded DNA molecules, above the size of several tens of kilo base pairs, are located solely inside DEX‐rich droplets. In contrast, short oligomeric single‐stranded DNA exists homogeneously without any apparent concentration difference. For the actins, G‐actins (monomeric) are evenly distributed, but F‐actins are localized inside DEX‐rich droplets. As in the picture, the existence of both F‐actin and DNA creates a specific structure in which DNA molecules are depleted by actin fibers arranged in parallel, something like the morphology of cell mitosis. The self‐emergence of characteristic morphologies in cell‐sized droplets could shed light on the underlying mechanism of the spatiotemporal self‐organization of living cellular systems. More information can be found in the communication by K. Takiguchi, K. Tsumoto, K. Yoshikawa, et al. on page 1370 in Issue 13, 2018 (DOI: 10.1002/cbic.201800066).