The transcription factor Zelda plays a pivotal role in promoting the maternal to 
zygotic transition during embryogenesis in Drosophila melanogaster. However, 
little is known about its role later in development. Here we are showing that 
Zelda is essential for proper wing development through gain and loss of function 
experiments. Zelda's transcript variants RB, RC and RD are present in imaginal 
wing discs of third instar larvae and the production of 2 protein isoforms of 
∼180 and ∼70kD was detected in the same tissue. In ChIP experiments using larval 
wing discs, Zelda was found to bind to a region of the optomotor-blind gene, 
suggesting an interaction with a Dpp target that promotes wing growth and 
patterning.