Figure 4.

The Thoracic Segments Generate the Output for a Turn

(A) Pattern of expression of the Gal4 lines used. The driver lines were crossed to the fluorescent reporter UAS-nuclear red fluorescent protein (nRFP). Anti-HRP staining was used to show the neuropile. tsh-Gal4 is expressed in the thoracic and abdominal segments [11]. In AbdA-Gal4, the gal4 is inserted in the largest intron of the abd-A transcription unit and reproduces the expression profile of Abd-A [23, 24] from the posterior half of A1 until the posterior half of A7 [25].

(B) Midline crossing defect as depicted by staining against Fas II. tsh>comm have midline crossing defects in thoracic and abdominal neuromeres, while aberrant crossing is only present in the abdominal segments of AbdA>comm larval nervous systems starting in segment A1, coinciding with the anterior boundary of AbdA expression (right panels). Magenta arrows indicate the anterior boundary of midline crossing defects.

(C) Number of forward and backward waves per minute.

(D) Duration of forward and backward waves in seconds.

(E) Number of pause turns per minute.

(F) Number of rearing events per minute.

(G and H) Representative tracks of male tsh>comm and AbdA>comm larvae.

A Kruskal-Wallis test with Dunn’s multiple comparison was used. Asterisk (^∗) indicates comparison with the same heterozygous driver line. ^∗p < 0.05; ^∗∗∗p < 0.001. + indicates comparison with UAS-comm/+. ⁺p < 0.05; ⁺⁺p < 0.01; ⁺⁺⁺p < 0.001. n_UAS-comm/+ = 23; n_tsh-Gal4/+ = 23; n_AbdA-Gal4/+ = 14; n_tsh>comm = 30; n_AbdA>comm = 19. Boxplots are described in the legend of Figure 2.