Sonic hedgehog (Shh)/Gli modulates the spatial organization of neuroepithelial cell proliferation in the developing chick optic tectum

摘要: Sonic hedgehog (Shh)/Gli pathway plays an important regulatory role on the neuroepithelial cells (NEc) proliferation in dorsal regions of developing vertebrate Central Nervous System. The aim this paper was to analyze effect Shh/Gli signaling activation dynamics and/or spatial organization NEc activity during early stages chick optic tectum (OT). In ovo pharmacological gain and loss function approaches were complemented with vivo electroporation experiments order create ectopic sources either Shh or Gli activator (GliA) proteins OT. proliferating analyzed at ED 4/4.5 by recording co-ordinates entire population mitotic (mNEc) located along OT dorsal-ventral sections. Several space signals (numerical sequences) derived from mNEc co-ordinate records different standardized non-linear methods signal analysis. pharmacologic treatment cyclopamine resulted dramatic failure expansion while agonist purmorphamine produced opposite result, a huge vesicle. Besides, GliA misexpressions interfere formation intertectal fissure midline. This morphogenetic alteration is accompanied increase density. There gradient response NEcs GliA: density maximal near decrease towards OT-tegmental boundary. Biomathematical analyses show that both electroporations change as revealed changes scaling index estimated these methods. present results critical modelling. probably mediated differential mitogenic increases modulates activity.