Flies expressing tau^GD8682 under the control of Scer\GAL4^GMR.PU show a rapid progressive pattern of retinal degeneration: whereas at 1 day post eclosion vacuoles are found only in the most proximal area of the retina, after one week the pattern of degeneration has spread about two thirds along the length of the retina. By four weeks the degeneration has progressed even further, encompassing almost the entire retina leaving only the cornea intact. When expression of tau^GD8682 is limited to the adult stages (by co-expressing Scer\GAL4^GMR.PU and shifting the flies to the restrictive temperature at eclosion) retinal degeneration is still observed at 20 days, although the phenotype is weaker than when tau^GD8682 is expressed throughout development. Raising the flies in the dark has no effect on the level of degeneration compared to flies kept in a light-dark cycle. Retinal defects are also observed at the ultrastructural level: 24-36 hours after eclosion retinas look highly disorganised and contain obvious vacuoles. The ommatidia contain fewer photoreceptor cells than normal, while the ommatidia that are present have abnormal rhabdomeres with loosened membranes, especially in proximity to the cell body. Developmental retinal defects are also observed. 73-78 hours after pupal formation the rhabdomeres are noticeably smaller, more disorganised and less compact than in wild type. All seven photoreceptors are still present. By the pharate adult stage the ommatidia have lost several photoreceptor cells and the rhabdomeres are severely deformed. A few vacuoles are also observed in the lamina of 3-day old flies.

No vacuoles are seen in the brains of 1-day old flies expressing tau^GD8682 under the control of Scer\GAL4^elav.PU, but are observed scattered throughout the brain at 14 days. When expression of tau^GD8682 is limited to the adult stages (by co-expressing Scer\GAL80^ts.αTub84B and shifting the flies to the restrictive temperature at eclosion) no vacuoles are seen in 1-day old flies but significant vacuolization is observed at 21 days.

One-day old flies expressing tau^GD8682 under the control of Scer\GAL4^elav.PU have more rounded axons surrounded by extracellular space, in contrast to the tightly packed, more irregularly shaped axons seen in wild type. Many of the axons have intracellular inclusions.

There is an increase in the average cross sectional area of the microtubules in 1-day old flies expressing tau^GD8682 under the control of Scer\GAL4^elav.PU compared to wild type. Microtubule density is also reduced: fewer microtubules are seen per neurite compared with wild type flies.

Adults expressing tau^GD8682 under the control of Scer\GAL4^elav.PLu (in the presence of Dcr-2^Scer\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.

Depending on the insertion line used, expression under the control of Scer\GAL4^Mef2.PR can result in viable flies or late pupal lethality.

Expression under the control of Scer\GAL4^pnr-MD237 results in a colour difference between the central Scer\GAL4^pnr-MD237 expression domain of the notum and the surrounding lateral region in 0% or 100% of the Scer\GAL4^pnr-MD237 expression domain, depending on the insertion line used.

Expression under the control of Scer\GAL4^pnr-MD237 may result in mild thorax closure defects, depending on the insertion line used.

Expression under the control of Scer\GAL4^pnr-MD237 may result in an enlarged notum, depending on the insertion line used.

Scer\GAL4^GMR.PU, tau^GD8682 has abnormal neuroanatomy phenotype, enhanceable by futsch^olk1

Scer\GAL4^elav.PU, tau^GD8682 has lethal phenotype, enhanceable by futsch^olk1

Scer\GAL4^GMR.PU, tau^GD8682 has abnormal neuroanatomy phenotype, non-suppressible by Map205^UAS.cBa, Scer\GAL4^GMR.PU

Scer\GAL4^GMR.PU, tau^GD8682 has abnormal neuroanatomy phenotype, non-suppressible by Map60^UAS.cBa, Scer\GAL4^GMR.PU

Scer\GAL4^GMR.PU, tau^GD8682 has retina phenotype, enhanceable by futsch^olk1

Scer\GAL4^GMR.PU, tau^GD8682 has lamina phenotype, enhanceable by futsch^olk1

Scer\GAL4^GMR.PU, tau^GD8682 has retina phenotype, non-suppressible by Map205^UAS.cBa, Scer\GAL4^GMR.PU

Scer\GAL4^GMR.PU, tau^GD8682 has retina phenotype, non-suppressible by Map60^UAS.cBa, Scer\GAL4^GMR.PU

Scer\GAL4^ppk.PU/tau^GD8682 is an enhancer of dendritic microtubule phenotype of Scer\GAL4^ppk.PU, chb^GL00367

Scer\GAL4^ppk.PU/tau^GD8682 is an enhancer of larval dorsal multidendritic neuron ddaC phenotype of Scer\GAL4^ppk.PU, chb^GL00367

tau^GD8682, Scer\GAL4^GMR.PU is an enhancer of retina phenotype of Hsap\MAPT^UAS.cAa, Scer\GAL4^GMR.PU