Spatially Coded Transformations in Gradient-Dependent Protocell Morphogenesis

Chemical gradients provide spatiotemporal signaling fields in various cellular processes, driving complex dynamic behaviours such as differentiation and spatial organization. Here we employ opposing gradients of two artificial morphogens (sodium dodecyl sulfate (SDS) and sodium phosphotungstate (polyoxometalate; POM)) to systematically investigate morphological differentiation in organized populations of coacervate microdroplet-based protocells. Using a matrix of 16 sets of counter-diffusive gradients, we classify the differentiated protocells into five phenotypes and encode their spontaneous organization into different spatially patterned protocell consortia using a 3-bit binary information system. We show that a predominant SDS gradient produces a diversity of differentiated phenotypes to generate complex spatially coded 2D protocell organizations. In contrast, a prevailing POM gradient decreases morphological differentiation, resulting in population homogenization. Our results improve our understanding of gradient concentration-dependent collective responses in synthetic microscale agents and provide a step to a new spatially resolved information encoding method with 3-bit binary outputs.