male sterile (with Df(3L)ED4416)
orb2Δ homozygotes that express orb2ΔA.T:Avic\GFP-EGFP, but not orb2+t18.7, exhibit a significant decrease in long-term memory in male courtship suppression assays, as compared to controls.
orb2Δ homozygotes that express orb2A.M51 show a significant decrease in long-term memory (1 and 2 days after training), but not short term memory (4 to 12 hours after training) in both male courtship suppression assays and associate appetite memory assays, as compared to controls.
As in wild type, orb2Δ mutant males exhibit inhibition of the female contact-induced male-male aggression seen in wild type males that have previously been exposed to females.
orb2Δ/orb2Δ80Q mutant flies exhibit defects in learned courtship suppression. When orb2Δ/orb2Δ80Q male flies are repeatedly exposed to the unreceptive female they suppress courtship for less than 24hr, compared with several days in wild type.
Heterozygous orb2Δ mutant flies exhibit defects in learned courtship suppression. When orb2Δ/+ male flies are repeatedly exposed to the unreceptive female they suppress courtship for less than 48hr, compared with several days in wild type.
Heterozygous orb2Δ mutant flies are defective in forming stable associative olfactory-reward memory. By 24 hours after training orb2Δ/+ mutant flies have a lower memory score than wild type flies.
orb2Δ homozygotes and orb2ΔQ/orb2Δ transheterozygotes do not exhibit any gross morphological defects, including in their overall brain and mushroom body anatomy.
Courtship behavior and short-term memory of courtship conditioning are both intact in orb2Δ and orb2ΔQ/orb2Δ mutants.
Courtship suppression (where the male understands if certain females are receptive to mating or not) is completely abolished in both orb2Δ and orb2ΔQ/orb2Δ mutants. orb2ΔQ/orb2Δ heterozygotes show an intermediate level of suppression, suggesting that orb2 levels may be a limiting factor in long-term memory formation.
orb2Δ is rescued by orb2+t18.7
orb2[+]/orb2Δ is rescued by orb2UAS.A.EGFP
orb2[+]/orb2Δ is rescued by orb2UAS.B.EGFP
orb2ΔQ/orb2Δ is rescued by Scer\GAL4fru.P1.D/orb2A.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4c747/orb2A.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4Mef2.247/orb2A.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4Tab2-201Y/orb2A.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL41471/orb2A.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4H24/orb2A.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4fru.P1.D/orb2B.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4c747/orb2B.UAS
orb2ΔQ/orb2Δ is rescued by Scer\GAL4Mef2.247/orb2B.UAS
orb2ΔQ/orb2Δ is not rescued by orb2A.UAS/Scer\GAL4c739
orb2ΔQ/orb2Δ is not rescued by Scer\GAL4c305a/orb2A.UAS
orb2ΔQ/orb2Δ is not rescued by Scer\GAL4GH146/orb2A.UAS
Expression of orb2+t18.7 rescues the courtship behavior defects seen in orb2Δ mutant males.
Expression of orb2F5Y partially rescues the courtship behavior defects seen in orb2Δ mutant males. Memory in these flies begins to decay after 36 hour and there was no measurable memory by 48-60 hours.
Expression of orb2Scer\UAS.A.T:Avic\GFP-EGFP under the control of Scer\GAL4drl-PGAL8 rescues the defects in forming stable associative olfactory-reward memory seen in orb2Δ/+ flies.
Expression of orb2Scer\UAS.B.T:Avic\GFP-EGFP under the control of Scer\GAL4drl-PGAL8 rescues the defects in forming stable associative olfactory-reward memory seen in orb2Δ/+ flies.
Expression of orb2F5Y partially rescues the defects in olfactory memory seen in orb2Δ mutant flies. No memory deficits are seen at 24 hours, but by 48 hours the flies have a lower memory score than wild-type flies.
Expression of orb2+t18.7 completely rescues the defects in olfactory memory seen in orb2Δ mutant flies.
Expression of orb2A.Scer\UAS or orb2B.Scer\UAS under the control of Scer\GAL4fru-GAL4, Scer\GAL4c747 or Scer\GAL4Mef2.247 restores 24 hour memory in orb2Δ/orb2ΔQ transheterozygotes.
Using the TARGET system (using Scer\GAL80ts.alphaTub84B to suppress Scer\GAL4 expression a certain points during development) to express either orb2A.Scer\UAS or orb2B.Scer\UAS (under the control of Scer\GAL4Mef2.247) in the mushroom bodies fully rescues long-term memory in orb2Δ/orb2ΔQ mutants when these flies are raised and tested at 29[o]C, but not when they are raised and tested at 18[o]C. Long-term memory is also restored when flies are raised at 18[o]C and then shifted to 29[o]C immediately after eclosion, thereby providing orb2 function only in the adults. The reciprocal experiment, in which flies are raised at 29[O]C, but shifted to 18[o]C as adults, does not restore long-term memory. Flies that are shifted up to 29[o]C just 2 hours before training show normal long-term memory, whereas those that are shifted immediately after training have no long-term memory. Conversely, flies shifted down to 18[o]C immediately after training have normal long-term memory, whereas flies shifted down to 18[o]C 24 hours before training, but then shifted up to 29[o]C immediately after training, do not.
Expression of orb2A.Scer\UAS in the mushroom body αβ neurons with the Scer\GAL4c739 driver, in the α'β neurons with the Scer\GAL4c305a, or in projection neurons with Scer\GAL4GH146 does not rescue the long-term memory defects found in orb2Δ/orb2ΔQ mutants.
Long-term memory is rescued in orb2Δ/orb2ΔQ mutants where orb2A.Scer\UAS is expressed in the γ neurons under the control of Scer\GAL4Tab2-201Y, Scer\GAL41471, or Scer\GAL4H24.
