Fig. 1: Defective motor coordination results in incomplete peristalsis in puc^E69 embryos.

a Mid-plane image of a stage 17 representative embryo (n = 10) carrying two GFP protein traps expressed at muscle Z-lines (w; G203; ZCL2144) (see Supplementary Movie 1). A selected segmented-line (highlighted in yellow) was employed to create kymographs spanning muscle units along the A/P axis (see below) at both sides of the embryo, right (R) and left (L). The evolution overtime of these kymographs was monitored live. Scale bar is 25 µm. b Intensity Profile plots generated along the segmented-line selection in (a). Gray values as a function of distance highlight the distribution of the segmental muscle units along the axis. Muscle contraction is detected by the differences in the distance between consecutive peaks at sequential time points. c Kymograph displaying muscle profiles from 17 to 25 hours AEL for the left side of the embryo in (a). Anterior (A) and posterior (P). Motor coordination maturation occurs in 5 stages of approximated stereotyped length⁸ (color coded): A, Intense unilateral twitching; B, general inactivity with occasional uncoordinated contractions; C, initiation of backward and forward peristalsis; D, pre-hatching inactivity period and E, complete peristalsis and specialized hatching head movements. d Representative kymograph displaying muscle profiles from 18 to 23 hours AEL, when the embryo dies, for the left side of a puc^E69 embryo (see Supplementary Movie 3). Anterior (A) and posterior (P). Motor coordination fails and embryos do not progress beyond the unilateral contraction period (stage A) (n = 13).