PATTERN-FORMATION IN THE VERTEBRATE NEURAL PLATE

Recent advances have been made in the understanding of the cellular an d molecular mechanisms involved in the formation and patterning of the neural plate of vertebrate embryos. Both planar and vertical signalin g Pathways appear to be involved in the neural induction and axial pat terning of the neural plate. The neural plate, behaving as a developme ntal field might be patterned by signals emanating from boundary regio ns: the organizer region and the midline and edges of the neural plate . Here, A. Ruiz i Altaba describes a possible model for anteroposterio r patterning involving planar signals for amphibian, avian and mammali an embryos, compares the axial patterning of the neural plate with the patterning of insect epithelia, and discusses possible roles of noggi n, follistatin and hedgehog-related genes in neural induction and patt erning.