Embryonic da dendrite screen – examples of phenotypes. (a) Cartoon showing the relative positions of cell bodies of dorsal cluster multidendritic (md) neurons in late stage 17 embryos. The dotted box indicates the region of dendritic field chosen for enlargement in each of (b',c',d',e',f'). (b,b') In control animals, the dendritic trees of the six da neurons in the dorsal cluster can be visualized with GAL4109(2)80 driving membrane-targeted GFP (UAS-mCD8::GFP). (c,c') Misexpression of GSd034: dilation of primary and reduced outgrowth of higher order dendritic branches. (d,d') Misexpression of GSd231: reduced dendritic field size with residual branching. (e,e') Slightly younger control animal, though still late stage 17, for comparison with (f,f'). (f,f') Misexpression of GSd422: production of filopodial spine-like protrusions. All images are maximal Z-projections of stacked confocal images. Anterior is left and ventral is down in all panels. Scale bar in (b) = 20 μm and applies to (c-f) also.