How are cells organized

biology: How cells become organisms

Vienna. The first few hours of a living being appear chaotic under the microscope. An egg divides again and again. Within a short time the new cells are jostling for position. "But in this apparently hellish turmoil, the cells begin to organize. Patterns form as the basis for tissue, organs and anatomical structures," report the Harvard Medical School and the Institute of Science and Technology (IST) Austria in Klosterneuburg.

This process is called morphogenesis. The team got to the bottom of it and found that the cells of animals learn certain "jobs" depending on where they are. To prevent the different cell types from getting mixed up, they stick together more firmly with their own work colleagues than with those from another profession, the researchers report in the journal "Science". This ensures a stable division for proper embryo development.

Carl-Philipp Heisenberg and his colleagues from IST examined the development of the "neural tube", the precursor of the central nervous system, in zebrafish. It is organized into several areas in which cells have different identities. Signal substances assign the cells their fate. Although they move during this development, cells of the same domain always come together because they stick to one another due to different adhesive proteins, also known as adhesion proteins. (Est)