Atypical Membrane Topology and Heteromeric Function of Drosophila Odorant Receptors In Vivo
(A) Schematic of the TARGET system.
(B) Immunostaining for OR83b (green) and OR22a/b (red) in Or83b null-mutant flies rescued using a UAS-Or83b transgene under the control of the TARGET system (Or22a-Gal4,tubP-Gal80ts/tubP-Gal80ts;UAS-Or83b,Or83b1/tubP-Gal80ts,Or83b2). Three copies of the tubP-Gal80ts transgene were used to ensure efficient suppression of GAL4 activity by GAL80 at 18 °C. Flies were cultured and aged as adults for 10 d at 18 °C and then incubated for a further 2 d either at 18 °C (top row) or at 29 °C (bottom row) to induce late expression of Or83b.
(C) Immunostaining for OR83b (green) and OR22a/b (red) in flies [genotype as in (B)] that were cultured and aged as adults for 3 d at 29 °C, transferred to 18 °C to switch off Or83b expression, and stained at the time points indicated.