title: Optix defines a neuroepithelial compartment in the optic lobe of the Drosophila brain.
abstract: BACKGROUND
  During early brain development, the organisation of neural progenitors into a neuroepithelial sheet maintains tissue integrity during growth. Neuroepithelial cohesion and patterning is essential for orderly proliferation and neural fate specification. Neuroepithelia are regionalised by the expression of transcription factors and signalling molecules, resulting in the formation of distinct developmental, and ultimately functional, domains.
  
  
  RESULTS
  We have discovered that the Six3/6 family orthologue Optix is an essential regulator of neuroepithelial maintenance and patterning in the Drosophila brain. Six3 and Six6 are required for mammalian eye and forebrain development, and mutations in humans are associated with severe eye and brain malformation. In Drosophila, Optix is expressed in a sharply defined region of the larval optic lobe, and its expression is reciprocal to that of the transcription factor Vsx1. Optix gain- and loss-of-function affects neuroepithelial adhesion, integrity and polarity. We find restricted cell lineage boundaries that correspond to transcription factor expression domains.
  
  
  CONCLUSIONS
  We propose that the optic lobe is compartmentalised by expression of Optix and Vsx1. Our findings provide insight into the spatial patterning of a complex region of the brain, and suggest an evolutionarily conserved principle of visual system development.
authors: Katrina S
authors: KS
authors: Gold
authors: The Gurdon Institute and Department of Physiology, Development & Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK. a.brand@gurdon.cam.ac.uk.
authors: Andrea H
authors: AH
authors: Brand
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster; D018398:Homeodomain Proteins / Q000378:metabolism*; D046569:Neuroepithelial Cells / Q000378:metabolism*; D009899:Optic Lobe, Nonmammalian / Q000196:embryology* / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C409102:Optix protein, Drosophila; D014157:Transcription Factors