Pax6-dependent Shroom3 expression regulates apical constriction during lens placode invagination.
Embryonic development requires a complex series of relative cellular movements and shape changes that are generally referred to as morphogenesis. Although some of the mechanisms underlying morphogenesis have been identified, the process is still poorly understood. Here, we address mechanisms of epithelial morphogenesis using the vertebrate lens as a model system. We show that the apical constriction of lens epithelial cells that accompanies invagination of the lens placode is dependent on Shroom3, a molecule previously associated with apical constriction during morphogenesis of the neural plate. We show that Shroom3 is required for the apical localization of F-actin and myosin II, both crucial components of the contractile complexes required for apical constriction, and for the apical localization of Vasp, a Mena family protein with F-actin anti-capping function that is also required for morphogenesis. Finally, we show that the expression of Shroom3 is dependent on the crucial lens-induction transcription factor Pax6. This provides a previously missing link between lens-induction pathways and the morphogenesis machinery and partly explains the absence of lens morphogenesis in Pax6-deficient mutants.
Plageman
Timothy F
TF
The Visual Systems Group, Children's Hospital Research Foundation, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039, USA.
Chung
Mei-I
MI
Lou
Ming
M
Smith
April N
AN
Hildebrand
Jeffrey D
JD
Wallingford
John B
JB
Lang
Richard A
RA
D000199:Actins / Q000502:physiology; D000818:Animals; D015815:Cell Adhesion Molecules / Q000502:physiology; D002460:Cell Line; D047108:Embryonic Development; D004847:Epithelial Cells / Q000502:physiology; D005136:Eye Proteins / Q000502:physiology*; D018398:Homeodomain Proteins / Q000502:physiology*; D007908:Lens, Crystalline / Q000196:embryology* / Q000254:growth & development; D051379:Mice; D008817:Mice, Mutant Strains; D008840:Microfilament Proteins / Q000235:genetics* / Q000502:physiology; D009024:Morphogenesis; D024462:Myosin Type II / Q000502:physiology; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000502:physiology*; D010750:Phosphoproteins / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology*; D000098662:Vasodilator-Stimulated Phosphoprotein
D000199:Actins; D015815:Cell Adhesion Molecules; D005136:Eye Proteins; D018398:Homeodomain Proteins; D008840:Microfilament Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D010750:Phosphoproteins; D012097:Repressor Proteins; C402112:Shrm protein, mouse; D000098662:Vasodilator-Stimulated Phosphoprotein; D024462:Myosin Type II