Fig. 3: Interference in the physiological function of early pioneers does not affect VNC condensation or embryos motor coordination.
a, c, e and g Representative kymographs displaying muscle activity profiles along 14 hours of development for embryos expressing TNT or Kir2.1 in RN2 [a (n = 5) and e (n = 3)] and CQ2 [c (n = 5) and g (n = 3)] neurons. For TNT, motor coordination maturation proceeds to D, the pre-hatching inactivity period, but never reached stage E, complete peristalsis or specialized hatching head movements (a and c). For Kir2.1, no effect was observed on motor coordination and the embryos hatched (e and g). b, d, f and h Representative Fas 2 expression profiles and cross-correlation matrices for 17 hours AEL embryos expressing TNT or Kir2.1 in RN2 [b (n = 3) and f (n = 3)] and CQ2 [d (n = 3) and h (n = 3)] neurons. The structural organization of the Fas2 axonal network is largely unaffected for TNT (b and d). For Kir2.1, the structural organization of the Fas2 axonal network was distorted and nodes' sizes and shape (black ellipses) were altered. i and j Quantification of the VNC length in μm (average and standard deviation) for each condition [TNT - i (n = 6 for RN2 controls, n = 4 for RN2 experimental, n = 10 for CQ2 controls and n = 15 for CQ2 experimental) and Kir2.1 - j (n = 6 for RN2 controls, n = 9 for RN2 experimental, n = 10 for CQ2 controls and n = 8 for CQ2 experimental)]. Statistically significant differences in length were detected only in RN2-Gal4<UAS-TNT embryos, using parametric student t-tests (*p = 0.0295) (p = 0.2394 for CQ2-Gal4<UAS-TNT, p = 0.8877 for RN2-Gal4<UAS-Kir2.1 and p = 0.7679 for CQ2-Gal4<UAS-Kir2.1). In grey are represented all the control conditions. RN2 and CQ2 conditions are shown in light green and dark green respectively. k Control Fas 2 cross-correlation matrix along the AP axis of the VNC of a stage 17 WT embryo stained with Fas 2. The color-coded representation shows the correlation level for each possible comparison at each position along the AP axis. One conspicuous node of robust correlation per segment was detected (black ellipse) (n = 8).
