Complex regulation of cyp26a1 creates a robust retinoic acid gradient in the zebrafish embryo.

ABSTRACT: Positional identities along the anterior-posterior axis of the vertebrate nervous system are assigned during gastrulation by multiple posteriorizing signals, including retinoic acid (RA), fibroblast growth factors (Fgfs), and Wnts. Experimental evidence has suggested that RA, which is produced in paraxial mesoderm posterior to the hindbrain by aldehyde dehydrogenase 1a2 (aldh1a2/raldh2), forms a posterior-to-anterior gradient across the hindbrain field, and provides the positional information that specifies the locations and fates of rhombomeres. Recently, alternative models have been proposed in which RA plays only a permissive role, signaling wherever it is not degraded. Here we use a combination of experimental and modeling tools to address the role of RA in providing long-range positio

SUBMITTER: White RJ 

PROVIDER: S-EPMC2080651 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature