.... Summary: Loss- and gain-of-function, and floor plate deletions, reveal that Shh that transits through the sclerotome is presented to the neuroepithelium from its basal aspect to affect motoneuron development. BMP Dermomyotome Dorso-ventral patterning Hb9 Motoneurons Myotome Neural tube Nkx...

.... Signals from dorsal and ventral ectoderm control dorso-ventral patterning while the apical ectodermal ridge (AER) controls bud outgrowth and patterning along the proximo-distal axis. We show, using cell-fate tracers, the existence of two distinct ectodermal compartments, dorsal versus ventral, in both...