Secreted signalling molecule forming concentration gradients that specify positional information. Classical: Bicoid, BMP, Shh, Wnt, retinoic acid. French-flag model (Wolpert 1969) predicts threshold responses.
Secreted signalling molecule forming concentration gradients that specify positional information. Classical: Bicoid, BMP, Shh, Wnt, retinoic acid. French-flag model (Wolpert 1969) predicts threshold responses.