The OK6 enhancer is predominantly restricted to motor neurons while the Cha (cholineacetyltransferase) enhancer is largely excluded from these cells. Images of ventral ganglia double labelled to reveal OK6 enhancer driven nuclear GFP (A) and Elav-expressing neurons (B). Similar images of ventral ganglia processed to compare Cha-driven n GFP (D) with Elav-labelled neurons (E). Cha-GAL4 expression in aCC neurons is shown by an arrowhead in 2D, E and F. Neuromuscular junctions (muscles 6 and 7) of animals expressing GFP under OK6 control show strongly fluorescent motor terminals (G). Figure 2H shows a stage 15 embryo expressing nuclear GFP driven by OK6-GAL4, counterstained with anti-elav to mark all differentiated neurons. GFP expression is only seen in salivary gland (asterisk) and some non-neuronal cells (arrowhead).