DMRT3 CONTROLS V0 INTERNEURON FORMATION AND IS REGULATED BY TCF3 AND RETINOIC ACID SIGNALLING IN ZEBRAFISH" (V0D IS CHANGED TO V0)

Abstract

Four distinct classes of interneurons, V0-V3, form in the ventral spinal cord during embryogenesis and are essential for coordination of motor behaviour in vertebrates. The dorsal-most V0 interneurons differentiate from P0 neural progenitors, at the border between dorsal and ventral spinal cord. How cell specification and balance between proliferation and differentiation are regulated in this region remains largely unknown. Here, I propose that zebrafish Dmrt3, a member of the DM domain containing transcription factor family, plays a key role in driving P0 progenitors into V0 interneurons. I show that dmrt3 starts to be expressed in late P0 progenitors after they exit the cell cycle, and acts to maintain expression of dbx1b and evx2, both homeobox genes implicated in V0 interneuron specification. Moreover, I could show that several signalling pathways, comprising RA, Shh, Fgf and Tcf3, work together to regulate dmrt3 expression and promote precise neurogenesis of V0 interneurons.