Fig. 3
From: A conserved odorant binding protein is required for essential amino acid detection in Drosophila
OBP19b expression in the proboscis. a Schematic representation of a Drosophila taste sensilla. Each sensillum ends with a terminal pore (P) and houses either two or four dendrites of gustatory receptors neurons (GRNs) and one mechanosensory neuron. Three accessory cells, thecogen (Th), tormogen (To), and trichogen (Tr), surround the GRNs. b, c OBP19b is expressed in the thecogen cells. The cellular distribution of OBP19b was examined based on the comparison and overlap (merge) of the spatial distribution of cell-type-specific markers (green) with OBP19b-Gal4 > UAS-mCherry transgenes (magenta). b Labeling of tormogen cells with ASE5-GFP. c Labeling of thecogen cells with nompA-GFP. Arrows point the most obvious overlapping between thecogen and OBP19b expressing cells. d Schematic representation of the repartition of labellum sensilla on the left hemi-proboscis. Taste sensilla are classified as a long (l; squares), intermediate (i; triangle), or short (s; circles) type depending on their length and relative position. The sensilla expressing OBP19b are labeled in magenta color. Asterisks indicate the sensilla containing a variable number (2–4) of taste neurons57,58,59. e Expression pattern of OBP19b in the thecogen cells of the proboscis sensilla. The three pictures represent three confocal layers taken from lateral to medial planes inside the left hemi-proboscis. N = 50, scale bars represent 50 µm.
