The isthmic organizer and brain regionalization.

摘要: Distinct neural identities are acquired through progressive restriction of developmental potential under the influence local environmental signals. Evidence for localization such morphogenetic signals at specific locations developing primordium has suggested concept "secondary organizer regions", which regulate identity and regional polarity neighboring neuroepithelial areas one step further. In recent years, most studied secondary been isthmic organizer, is localized hind-midbrain transition controls anterior hindbrain midbrain regionalization. Otx2 Gbx2 expression fundamental positioning establishment molecular interactions that induce Fgf8 then, stabilize autoregulative loop En1, Wnt1 Pax2 expression. Temporospatial patterns gene expressions necessary correct development which, by a planar mechanism induction, normal rostral from r2 to midbrain-diencephalic boundary. appears as active diffusible molecule activity be effector in other inductive activities revealed regions.