The expression of EcRB1-ΔC655.F645A.UAS under the control of Scer\GAL4byn-Gal4 throughout metamorphosis results in adults that die soon after eclosion, show an enlarged pylorus and lacking ileum histolysis.
Expressing EcRB1-ΔC655.F645A.UAS under the control of Scer\GAL4CCAP.PP results in the loss of most CCAP neurons in wandering third instar larvae and severely defective pupal development, characterized by a failure in head eversion and shortened wings and legs.
Expression of EcRB1-ΔC655.F645A.UAS under the control of Scer\GAL4NP3056, Scer\GAL4orb-0449-G4 or Scer\GAL4lilli-189Y in combination with a Gal80[ts] transgene to restrict expression to between late third instar larva and 24 hours after puparium formation, results in the retention of larval innervation patterns of these antennal lobe local interneurons that are lost from controls during metamorphosis.
Expression of EcRB1-ΔC655.F645A.Scer\UAS in salivary glands during embryonic and early larval stages does not affect normal development.
Expression of EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4c42 results in delayed development and larval lethality at the early first instar stage. Larvae are smaller in size, slow moving, and display gross abnormalities including low adipose tissue, transparent cuticle and deformed Malpighian tubules.
Malpighian tubule defects of first instar larvae expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4c42 include reduction in overall size, failure to properly elongate and remaining coiled, smaller mean diameter, reduction of the number of and irregular distribution of stellate cells and principal cells in anterior and posterior Malpighian tubules, and reduction in uric acid deposition as compared to wild type.
Animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Sgs3.PD show normal mid-third instar (wandering behaviour) and late larval (everting anterior spiracles, barrel shape, midgut programmed cell death) ecdysone-triggered responses. The prepupal ecdysone-triggered responses (head eversion, wing and leg inflation and leg extension) also occur normally. In the salivary gland, mid-third instar glue synthesis, late larval glue secretion and prepupal salivary gland programmed cell death are all defective.
Expression of EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Sgs3.PD blocks the formation of the large acidic structures which normally occurs in salivary gland cells approximately 1.5 hours after head eversion, and also blocks caspase activation at 2 hours after head eversion. This results in a persistent salivary gland phenotype at 24 hours after puparium formation.
Expression of EcRB1-ΔC655.F645A.Scer\UAS in astrocytes, under the control of Scer\GAL4alrm.PD, does not affect astrocyte morphology in 3rd instar larvae. However, EcRB1-ΔC655.F645A.Scer\UAS expression completely blocks their morphological transformation into the highly vacuolated morphology apparent in controls at 6 hours after pupal formation.
Astrocyte morphological transformation can be suppressed when EcRB1-ΔC655.F645A.Scer\UAS is expressed in one to two astrocytes, using MARCM, rather than the entire population. EcRB1-ΔC655.F645A.Scer\UAS expression block the induction of phagolysomal activity.
Over 95% of larvae expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4ETH.Switch in the presence of RU486 have multiple mouthparts (indicating a failure to complete ecdysis), and approximately 70% of these animals die as larvae.
Severing of the dendrites of ddaC neurons occurs in animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4repo does occur, albeit with some delay. However, the glial membranes that wrap the proximal dendrites as part of this dendrite pruning process show very little sign of retraction or disintegration by 16 hours after puparium formation and the wrapped dendrite segments remain intact. This defect persist until the death of the neurons during metamorphosis.
Induction of EcRB1-ΔC655.F645A.Scer\UAS during 0-30 hours after pupal formation (under the control of Scer\GAL80ts.αTub84B and Scer\GAL4wg-IS650) blocks apoptosis and results in rearrangement of the wing margin cells. In addition, blocking ecdysone signalling results in overlap of the double-row hairs in the adult wing.
Larvae expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of either Scer\GAL4tsh-c724 or Scer\GAL4c649 are smaller in size than age-matched controls, with the reduction in size being greatest with the Scer\GAL4tsh-c724 driver.
Larvae expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4c649 contain both first and second instar larval mouth hooks (showing a defect in moulting) at a time when control larvae have already reached the third larval instar stage.
The mean diameter of the Malpighian tubules of larvae expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of either Scer\GAL4tsh-c724 or Scer\GAL4c649 is smaller than that of controls, with the decrease being greatest with the Scer\GAL4tsh-c724 driver. The number of principal cells in the anterior and posterior Malpighian tubules of the mutant larvae is similar to that in wild type. However, the number of stellate cells in the mutant anterior and posterior Malpighian tubules is reduced compared to wild type, with the reduction being greatest with the Scer\GAL4tsh-c724 driver. In addition, the distribution of the stellate cells is altered in the mutant tubules, so that they are present in clusters instead of being evenly distributed as occurs in wild type.
High expression of EcRB1-ΔC655.F645A.Scer\UAS in muscle under the control of Scer\GAL4C57 results in first-instar larval lethality. Lower expression under the control of Scer\GAL4Mhc.PW leads to pupal lethality. Expression under the control of Scer\GAL4Mhc.PW produces a delay in synapse elimination due to post-synaptic disruption of EcR signaling.
Expression of EcRB1-ΔC655.F645A.Scer\UAS postsynaptically (under the control of Scer\GAL4Mhc.PW) results in the complete blockage of both pre- and post-synaptic synapse elimination in pupae 9 hours after puparium formation.
Expression of EcRB1-ΔC655.F645A.Scer\UAS in larval epidermal cells, under the control of Scer\GAL4NP0056, blocks the ability of these cells to constrict, extrude and undergo apoptosis. As a result, abdominal morphogenesis does not succeed and larval epidermal cells remain in the abdomen of pharate adult flies, forming part of the epidermis.
Thoracic ventral neurosecretory cells that express EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Fmrf.PS are of normal size and larval morphology at the start of metamorphosis. However, these mutants show defective neuronal remodelling during metamorphosis. The axons show much lower levels of pruning compared to wild-type cells and show no filopodia during the pruning phase. EcRB1-ΔC655.F645A.Scer\UAS-expressing neurons start extending filopodia after 24 hours APF from the neurohemal organ and in the growth zone below. As this happens, the remnant neurohemal organ partially fragments, resulting in an adult-like arbor with clumped varicosities and a dense centre. Effects on adult axon outgrowth are relatively mild, with axonal arbors slighlty reduced compared to controls.
Inhibition of ecdysone signalling by expression of EcRB1-ΔC655.F645A.Scer\UAS under the regulation of Scer\GAL4ppk.PG results in C4da neurons losing their ability to initiate larval dendrite pruning at 20 hours after pupal formation, with approximately 90% of large dendritic branches being retained after head eversion.
Expression of EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Tab2-201Y results in lethality at late pupal stages. Mushroom body axons are not pruned during pupal development in these animals (in contrast to wild type). Infiltration of glial processes into the mushroom body lobes is severely suppressed during early pupal development compared to wild-type pupae.
When expression is governed by Scer\GAL4Lsp2.PH in the larval fat body early autophagosomal structures are able to form but do not acidify, perhaps due to a failure to fuse with lysosomes.
Expression of EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Act5C.PI results in lethality either during embryonic development or soon after hatching. Expression of EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4GMR.PF usually results in animals ceasing development after pupariation. Escapers have defective eyes, with poorly pigmented ommatidia and large necrotic, melanised patches. At 25oC, most animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4dpp.blk1 fail to pupate. At 20oC, some animals arrest before pupation, while most pupate but die during adult development. Escapers are morphologically normal except for the orientation and sometimes length of the posterior scutellar bristles. Animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Ser.PGF fail to pupate. Pupariation is defective in animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Eip71CD.657; the animals fail to shorten and tanning occurs only at the extremities (where the Scer\GAL4Eip71CD.657 driver is not expressed). The imaginal discs do not evert. The salivary glands histolyse on schedule at pupation in animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Sgs3.PD. The polytene chromosomes are normal in size, but their puffing pattern in white prepupae remains blocked at puff stage 1' (PS1'), a stage normally seen only early in the third larval instar. The fat body cells fail to dissociate at pupation in animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Lsp2.PH. Most of the animals die late in adult development. Viability is lower in females than in males. Most animals expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4Eh.0.8 moult into adult but fail to expand their wings. Border cell migration is delayed or fails completely in females expressing EcRB1-ΔC655.F645A.Scer\UAS under the control of Scer\GAL4slbo.2.6. The chorion structures are fragile and eggs derived from these females collapse soon after oviposition. Dorsal appendages are frequently broad or branched and operculum structures are poorly developed.
When EcRB1-ΔC655.F645A.Scer\UAS is driven by Scer\GAL4GMR.PF massive necrosis is seen in the eye, resulting in a collapse of the domed shape of the eye, a large decrease in the level of pigmentation. poorly defined facets and a very characteristic scar.