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Rab23 GTPase is expressed asymmetrically in Hensen's node and plays a role in the dorsoventral patterning of the chick neural tube
Author(s) -
Li Naixin,
Volff JeanNicolas,
Wizenmann Andrea
Publication year - 2007
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.21331
Subject(s) - neural tube , biology , gastrulation , floor plate , microbiology and biotechnology , anatomy , sonic hedgehog , neurogenesis , neural plate , spinal cord , mesoderm , otic vesicle , embryo , embryogenesis , neuroscience , gene , embryonic stem cell , gene expression , signal transduction , genetics , in situ hybridization
The mouse Rab23 protein, a Ras‐like GTPase, inhibits signaling through the Sonic hedgehog pathway and thus exerts a role in the dorsoventral patterning of the spinal cord. Rab23 mouse mutant embryos lack dorsal spinal cord cell types. We cloned the chicken Rab23 gene and studied its expression in the developing nervous system. Chick Rab23 mRNA is initially expressed in the entire neural tube but retracts to the dorsal alar plate. Unlike in mouse, we find Rab23 in chick already expressed asymmetrically during gastrulation. Ectopic expression of Rab23 in ventral midbrain induced dorsal genes ( Pax3 , Pax7 ) ectopically and reduced ventral genes (Nkx2.2 and Nkx6 ) without influencing cell proliferation or neurogenesis. Thus, in the developing brain of chick embryos Rab23 acts in the same manner as described for the caudal spinal cord in mouse. These data indicate that Rab23 plays an important role in patterning the dorso‐ventral axis by dorsalizing the neural tube. Developmental Dynamics 236:2993–3006, 2007. © 2007 Wiley‐Liss, Inc.