Embryos from mothers expressing Rab5^S43N.UAS under the control of Scer\GAL4^{VP16.mat.αTub67C} show smaller yolk granules. These embryos show increased microtubule growth in cold-induced microtubule regrowth assays.

Adults expressing Rab5^S43N.UAS under the control of Scer\GAL4^elav.PLu do not exhibit climbing defects compared to control

Expressing Rab5^S43N.UAS under the control of Scer\GAL4^ppk.PU induces enlarged endosomes but does not affect mitochondria localization in white prepupal ddaC neurons' cell bodies, as compared to controls.

Scer\GAL4^He.PZ-driven expression of Rab5^{S43N.Scer\UAS} induces increase in the number of circulating hemocytes in third instar larvae relative to controls.

The third instar larval neuromuscular junction of individuals expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^da.G32 exhibits the accumulation of large presynaptic endocytic vesicles, as compared to controls.

Animals expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^grh.D4 are lethal, show defects in larval dorsal trunk elongation (resulting in internalization of posterior spiracles into the body cavity) and the larvae are smaller than age-matched controls.

Expression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^{SPARC-MI00329-GAL4} results in elongation of the ventral nerve cord.

Third larval instar adipocytes expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^{SPARC-MI00329-GAL4} show a significant increase in plasma membrane depth compared to control cells.

The class IV dendritic arborization neurons in flies expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^ppk.PG show a significant decrease in the complexity of dendritic arbors.

Third instar larvae expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^VGlut-OK371 show a significant increase in the number of boutons per muscle area at the neuromuscular junction (NMJ) compared to controls and the boutons are smaller than normal. Class IV da neurons show mild defects in dendrite morphogenesis: total dendritic length is decreased by 11% and the number of branch endings per cell is decreased by 19%, while the coverage index is not altered.

Adults expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^VGlut-OK371 show a significant increase in the number of boutons per muscle area at the neuromuscular junction (NMJ) compared to controls.

Expression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^da.G32 affects dorsal closure. The amnioserosa cells are irregular in shape with big lamellipodia during the early stages of dorsal closure. Later on, epidermal elongation is impaired and puckering is seen. Dorsal closure fails, with the embryos having a conspicuous dorsal hole in the cuticle.

Expression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^c381 results in changes in amnioserosa cell morphology during early and late stages of dorsal closure, but epidermal cell elongation is not compromised and the embryos complete dorsal closure.

Expression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^en-e16E has no visible effect on dorsal closure.

Third-instar larval eye discs expressing dominant negative Rab5^{S43N.Scer\UAS} in the posterior region of the under control of Scer\GAL4^GMR.PF display normal morphology, with differentiating R-cells in the eye disc expressing normal R-cell developmental markers. However, many R-cell nuclei fail to maintain their apical localization and instead mis-localize basally.

Embryos expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^69B demonstrate over-elongated dorsal trunks.

Mutant neurons in the third instar larva expressing Rab5^{S43N.Scer\UAS} show reduced branch numbers and sprout much less in the proximal area than wild-type neurons. Neurons expressing Rab5^{S43N.Scer\UAS} extend axons and major dendritic branches, however, they display greatly simplified dendritic arbors and decreased number of terminal branches compared with that found for wild-type neurons.

No third instar larvae could be recovered that express Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^en-e16E. Viable larvae can be obtained when Rab5^{S43N.Scer\UAS} is expressed under the control of Scer\GAL4^C5. The wing discs of these larvae contain misfolded tissue that contains apoptotic cells. Expression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^Bx-MS1096 or Scer\GAL4^C96 also causes apoptosis in the wing disc.

A few clones expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^Act5C.PI can be recovered in the wing pouch of wandering third instar larvae, although these become extruded from the epithelium or are lost through cell death.

Overexpression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^bbg-C96 results in the loss of wing tissue.

Overexpression of Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^C5 results almost complete loss of wing tissue.

Expression of Rab5^{S43N.Scer\UAS} in border cells, driven by Scer\GAL4^slbo.2.6, results in the absence of the apical cap in stage 8 egg chambers, as compared with wild type. Among clusters still showing a cap, 47% show a micro cap. The migration of border cell clusters to the oocyte is defective.

Blocking endocytosis in border cells by expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^slbo.2.6 delays the migration of these cells.

The average number of crystal cells per embryo is reduced compared to wild type in stage 13-14 embryos expressing Rab5^{S43N.Scer\UAS} under the control of Scer\GAL4^srp.

Expression of dominant-negative Rab5^{S43N.Scer\UAS} under the regulation of Scer\GAL4^elav-C155 at low levels during embryonic and early larval stages at 16^oC and at higher levels at 25^oC during the last two days of larval development does not cause a developmental phenotype of the neuromuscular junctions. The synaptic surface area is normal in Rab5^{S43N.Scer\UAS}-expressing synapses. In addition, Rab5^{S43N.Scer\UAS}-expressing motoneurons display a normal number and morphology of endocytosis centers and active zones of exocytosis. In Rab5^{S43N.Scer\UAS} synapses (under the regulation of Scer\GAL4^elav-C155) small, 70nm vesicles are more frequently observed than in wild-type, indicating that these endocytic vesicles are unable to fuse efficiently with early endosomes. In wild-type and Rab5^{S43N.Scer\UAS} (Scer\GAL4^elav-C155) synapses, FM1-43 styryl dye recycling experiments reveal that the rate of FM1-43 internalisation is 2.5-fold slower in Rab5^{S43N.Scer\UAS} synapses compared to wild-type. Synapse release is also affected in Rab5^{S43N.Scer\UAS} mutants. FM1-43-release experiments reveal that release occurs 2.5 times slower during the first 5min in Rab5^{S43N.Scer\UAS} synapses compared to wild-type, indicating that impaired Rab5 function reduces small vesicle release. Miniature excitatory junction potential (mEJP) recordings from Rab5^{S43N.Scer\UAS} mutant neuromuscular junctions display no significant differences in mean frequency, amplitude, variability, or voltage decay kinetics compared to wild-type mEJPs. This indicates that presynaptic expression of Rab5^{S43N.Scer\UAS} does not affect the vesicular neurotransmitter content, the number of fusion competent vesicles, or the postsynaptic glutamate receptor function or density. Consistently, a normal number of docked vesicles is observed at the ultra-structural level, and no difference in the overall morphology, synaptic surface area, or active zones is detected. Mean quantal content decreases by around 50% in Rab5^{S43N.Scer\UAS}; Scer\GAL4^elav-C155 neuromuscular junctions. Rab5^{S43N.Scer\UAS}, under the regulation of Scer\GAL4^elav-C155 does not significantly alter the synaptic area, nor the active zone density of presynaptic terminals, implying that the total number of active zones is normal.