Expression of ttvGD1993 under the control of Scer\GAL4elav-C155 leads to a net increase in autophagy (assessed by proteolytic cleavage of mCherry-Atg8a) relative to controls.
Expression of ttvGD1993 in larval epidermal cells under the control of any following: Scer\GAL4A58, Scer\GAL4hh-Gal4, Scer\GAL4GMR10C12 or Scer\GAL4GMR16D01 results in severe reduction in terminal dendrite density as well as terminal dendrite number (with all except the Scer\GAL4A58 driver) within the intersegmental area in the adjacent class IV dendritic arborizing (da) neurons; the effect is apparent in first instar larvae already (at 24hr after egg laying, AEL) and becomes more pronounced as the larvae develop. Some differences in the dendrite length are observed also in the other three classes of da neurons but are much milder than in class IV neurons: The total dendrite length is slightly reduced in class I ddaD neurons but increased in class I ddaE neurons and in class II ddaB neurones (all with Scer\GAL4A58 driver), in class III ddaA neurons a slight decrease is observed in the dendritic tree length overall, as well as in total length and number of terminal dendrites, whereas no significant differences in any of these categories are found in ddaF neurons (with the Scer\GAL4hh-Gal4 driver) relative to control larvae. Long-term time-lapse imaging analysis of dendrite dynamics in larval class IV da neurons between 72 hr and 84 hr AEL in Scer\GAL4hh-Gal4>ttvGD1993 animals revealed that the high-order dendrites are highly dynamic at the border of the ttv knock-down zone - they can extend relatively far into this zone but are only transient and there is no obvious net increase in dendrite number or density over time. This is however not due to an intrinsic inability of da dendrites to permanently invade empty spaces at this stage.
The areas of dendritic arbor of class IV neurons directly adjacent to wild-type epidermal cells that are completely surrounded by flip-out clones of epidermal cells expressing ttvGD1993 under the control of Scer\GAL4Act5C.PI do not display any decrease in the density of terminal dendrites on the contrary, the density is significantly increased compared to controls with wild-type clones.
Adults expressing ttvGD1993 under the control of Scer\GAL4elav.PLu (in the presence of Dcr-2Scer\UAS.cDa to increase the efficiency of RNAi) do not show a significant defect in avoidance of noxious temperature (46[o]C) compared to control flies.