NOTCH SIGNALING IN DEVELOPMENT - ON EQUIVALENCE GROUPS AND ASYMMETRICDEVELOPMENTAL POTENTIAL

Notch-mediated lateral signalling takes place between equivalent cells that then adopt alternative fates. An example is the epidermal-neural choice in the Drosophila neuro-ectoderm. Sometimes this choice is ran dom. Sometimes it is biased to a preferred cell by an extrinsic signal . Sometimes the neural precursor is predetermined. A stochastic outcom e is probably older in evolutionary terms.