Reach Out and Touch Someone Pernille Rørth Science 21 February 2014: 343 (6173), 848-849. [DOI:10.1126/science.1250885]
Abstract:
How do cells in the body communicate over long distances? Neurons do so through long cellular extensions—axons and dendrites—that establish direct contacts (synapses) with target cells. Other cells are thought to receive information through secreted signaling molecules that diffuse through a tissue. For example, cells that become the fingers of the hand receive patterning information from one side of the limb primordia, with the proximal cells receiving more signal than the distal ones and, as a consequence, taking on a different digit identity. On page 852 of this issue, Roy et al. (1) provide evidence that signal-receiving cells do not passively wait, but reach out and grab the signal by making direct contact with signal-sending cells (see the figure).