PATTERN-FORMATION IN THE VERTEBRATE NEURAL PLATE

Recent advances have been made in the understanding of the cellular and molecular mechanisms involved in the formation and patterning of the neural plate of vertebrate embryos. Both planar and vertical signaling Pathways appear to be involved in the neural induction and axial patterning of the neural plate. The neural plate, behaving as a developmental field might be patterned by signals emanating from boundary regions: the organizer region and the midline and edges of the neural plate. Here, A. Ruiz i Altaba describes a possible model for anteroposterior patterning involving planar signals for amphibian, avian and mammalian embryos, compares the axial patterning of the neural plate with the patterning of insect epithelia, and discusses possible roles of noggin, follistatin and hedgehog-related genes in neural induction and patterning.