TY - JOUR T1 - Neural tube development depends on notochord-derived Sonic hedgehog released into the sclerotome JF - bioRxiv DO - 10.1101/639831 SP - 639831 AU - Nitza Kahane AU - Chaya Kalcheim Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/05/15/639831.abstract N2 - Sonic hedgehog (Shh) is necessary both for neural and mesodermal development. By loss and gain of Shh function, and floor plate deletions, we report that Shh released from notochord into sclerotome constitutes a dynamic pool of ligand serving both tissues. Depletion of Shh in sclerotome by membrane-tethered hedgehog-interacting protein or by Patched1, but not by a dominant active version of Patched, reduced motoneuron numbers and also compromised myotome differentiation. These effects were a specific and direct consequence of reducing Shh. In addition, grafting notochords in a basal, but not apical location vis-a-vis the tube, profoundly affected motoneuron development, suggesting that initial ligand presentation occurs at the basal side of epithelia corresponding to the sclerotome-neural tube interface.Collectively, our results reveal the sclerotome as a previously unknown common pool and potential site of a Shh gradient that coordinates development of mesodermal and neural progenitors. ER -