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. 2020 Jun 25;9:e54978. doi: 10.7554/eLife.54978

Figure 7. Motor control of the rostrum.

(A–E) CsChrimson activation of split GAL4s for rostrum motor neurons, compared to controls (unfilled), quantifying change in proboscis position from rest (total extension of proboscis at maximum movement divided by at rest; therefore no movement = 1) (A), change in rostrum angle from rest (B), change in haustellum angle from rest (C), change in rostrum angle from a protracted position during feeding (D), and change in haustellum angle from an extended position during feeding (E). (F–J) TNT silencing of split GAL4s for rostrum motor neurons, compared to controls, quantifying proboscis position at rest (F), rostrum angle at rest (G), haustellum angle at rest (H), change in rostrum angle from rest to feeding position (I), and change in haustellum angle from rest to feeding position (J). Bar: mean. Biological replicates, n = 14–16 flies/genotype. Asterisks: unpaired t-tests, experimental (colored) vs. each control (showing least significant), with multiple testing correction. *p<0.05, **p<0.01, ***p<0.001, no asterisk, not signficant. See Methods for further explanations of metrics shown. (K–L) Sagittal schematics of proboscis movements controlled by muscle 9 (green): protraction of rostrum and extension of haustellum (arrows). Muscle 9 origin: ventral wall of head. Muscle 9 insertion: internal part of rostrum cuticle (asterisk). Proboscis segments (dark gray) pivot around joints (magenta dots). (M–O) Proboscis movements controlled by muscles 1, 2D and 2V (colored): retraction of rostrum and haustellum (arrows). Muscle origins: posterior wall of head. (P–Q) Frontal view of whole-mount heads (blue) with segmented muscles (green, numbered) and the apodeme within the rostrum (white) that swings outward during rostrum extension, shown with rostrum retracted (P) or extended (Q). Scale bar: 50 µm.

Figure 7.

Figure 7—figure supplement 1. Examples of rostrum muscle actions.

Figure 7—figure supplement 1.

(A–B) Example mn9 phenotype: extension of both the rostrum and haustellum in response to CsChrimson activation (B), compared to resting proboscis before the stimulus (A). (C–D) Example retractor phenotype: retraction of the rostrum in response to CsChrimson activation of mn1 (D), compared to feeding position before the stimulus (dotted line) (C).
Figure 7—figure supplement 2. Raw joint angles, not normalized, for all motor neurons from Figures 7–9.

Figure 7—figure supplement 2.

(A–B) CsChrimson activation of split GAL4s for the motor neurons shown, quantifying raw rostrum angle in a protracted position during feeding (A) and raw haustellum angle in an extended position during feeding (B). (C–D) TNT silencing of the same split GAL4s, quantifying maximum raw rostrum angle during feeding (C) and maximum raw haustellum angle during feeding (D). Bar: mean. Biological replicates, n = 14–16 flies/genotype. Asterisks: unpaired t-tests, experimental (colored) vs. each control (unfilled), showing least significant, with multiple testing correction. *p<0.05, **p<0.01, ***p<0.001, no asterisk, not significant.