Fig. 1
From: Sensory neuron lineage mapping and manipulation in the Drosophila olfactory system
A genetic immortalization labeling system for OSN lineages. a Schematic of Drosophila peripheral olfactory system development and the genetic immortalization strategy. b Schematic of the larval eye-antennal imaginal disc; olfactory SOPs develop in the A3 region (blue). PA presumptive arista zone. c Schematic of the Drosophila head, illustrating a single population of OSNs expressing the same olfactory receptor (green); these project axons from the antenna at the periphery towards a unique glomerulus in the antennal lobe in the brain (dashed box). d Row 1: nonimmortalized enhancer-GAL4-driven expression of myr:GFP (green) in 2 h APF antennal discs (except for ato-GAL4 and amos-GAL4, which show 4 h APF discs, due to the delayed expression of these drivers). The discs are colabeled with α-Amos (red) and α-Dac (blue) to provide spatial landmarks. Rows 2–3: nonimmortalized enhancer-GAL4-driven expression of myr:GFP (green) in the axon termini of OSNs innervating the right antennal lobe of the adult. The glomerular structure of the lobe is visualized with α-Bruchpilot (nc82, magenta); anterior and posterior focal planes (single optical slices) are presented to show the majority of glomeruli. Rows 4–5: immortalized enhancer-GAL4-driven expression of rCD2:GFP (green) in OSN axons, presented as in rows 2–3. The immortalization time window was 4 h BPF-20 h APF, during which the SOPs undergo maturation (Fig. 1a). Note that the immortalized enhancer-GAL4s (rows 4–5) label different subsets of OSNs from their nonimmortalized counterparts (rows 2–3). Scale bars = 20 µm. The genotypes of the flies presented in the figures are listed in Supplementary Table 1. e Heatmap showing the frequency that a given antennal lobe glomerulus is innervated by OSN axons labeled by a GFP reporter (myr:GFP or rCD2:GFP) under the control of a nonimmortalized or immortalized enhancer-GAL4 driver. sac sacculus sensilla, pb maxillary palp basiconic sensilla; see text for other abbreviations. The number of antennal lobes scored (n) is indicated on the right. Immortalization was performed during the same time window (4 h BPF-20 h APF) for all drivers except for late en-GAL4 immortalization (9 h APF-39 h APF)
