Slit1b-Robo3 signaling and N-cadherin regulate apical process retraction in developing retinal ganglion cells.
When neurons exit the cell cycle after their terminal mitosis, they detach from the apical surface of the neuroepithelium. Despite the fact that this detachment is crucial for further neurogenesis and neuronal migration, the underlying mechanisms are still not understood. Here, taking advantage of the genetics and imaging possibilities of the zebrafish retina as a model system, we show by knockdown experiments that the guidance molecule Slit1b and its receptor Robo3 are required for apical retraction of retinal ganglion cells (RGCs). In contrast, N-cadherin seems to be responsible for maintenance of apical attachment, as expression of dominant-negative N-cadherin causes RGCs to lose apical attachments prematurely and rescues retraction in slit1b morphants. These results suggest that Slit-Robo signaling downregulates N-cadherin activity to allow apical retraction in newly generated RGCs.
Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom.
Grace K W
GK
Wong
Marie-Laure
ML
Baudet
Caren
C
Norden
Louis
L
Leung
William A
WA
Harris
D000818:Animals; D030801:Animals, Genetically Modified; D015820:Cadherins / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000502:physiology*; D011971:Receptors, Immunologic / Q000502:physiology*; D012160:Retina / Q000166:cytology / Q000196:embryology*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000378:metabolism*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000502:physiology*; D000097905:Roundabout Proteins
D015820:Cadherins; D009419:Nerve Tissue Proteins; D011971:Receptors, Immunologic; D029961:Zebrafish Proteins; C513786:N-cadherin, zebrafish; C499626:robo3 protein, zebrafish; D000097905:Roundabout Proteins; C492286:slit1b protein, zebrafish