Figure 4. DSK Functions Downstream of a subset of P1 Neurons to Modulate Fighting Behavior.
(A) Transsynaptic labeling by trans-Tango method identifies DSK neurons as postsynaptic partners of a subset of P1 neurons. Expression of the trans-Tango ligand in a subset of P1 neurons (red) (A1) induces postsynaptic signals (anti-HA, magenta) (A2) in the central brain. Green, anti-DSK antibody staining (A2). (A3–A5) and (A6–A8) are enlargements of dashed boxes in (A2). Genotypes of a subset of P1 neurons (P1a split-GAL4): +/y; R15A01.AD/R15A01.AD; R71G01-GAL4.DBD/R71G01-GAL4.DBD. (B) GRASP signals (B1) reveal synaptic connections between R71G01-LexA labeled P1 Neurons and DSK neurons. spGFP1–10 is expressed by DskGal4 drivers; spGFP11 is driven by the R71G01-LexA. Magenta, anti-DSK antibody. (B4–B6) are enlargements of the dashed box in (B3). White arrowheads point to areas in which GRASP signal co-localized with synaptic boutons revealed by anti-DSK antibody staining (B6). Scale bars represent 50 μm in (A1–A2, B1–B3). Scale bars represent 5 μm (A3–A8, B4–B6). (C) Dendrites of DSK neurons revealed by DskGAL4 driven UAS-Denmark expression (red). Axons of a subset of P1 neurons revealed by P1a split-GAL4 driven UAS-sytGFP expression (green). nc82 antibody (blue) was used to label neuropils. Scale bars represent 50 μm. (D–E) Enlargements of dashed boxes in (C). White arrowheads point to areas in which a subset of P1 axons and DSK dendrites overlap. Scale bars represent 5 μm. (F and G) Number of lunges per minute after initiation (F) and fighting latency (G) during thermogenetic activation of a subset of P1 neurons in the ΔDsk mutant background. The aggression-promoting effect of activating a subset of P1 neurons is suppressed by the ΔDsk mutants. ***p<0.001, n.s. indicates no significant difference (Kruskal-Wallis and post-hoc Mann-Whitney U tests).