(A–B'''') timepoints from representative videos (see Figure 4—video 1) of myocardial cells whose membrane has been labeled with myl7:lck-eGFP (black), medial to the right, in a DMSO- (A–A'''') or a 20 μM LY- (B–B'''') treated embryo. Red arrowheads indicate representative protrusions, which are mostly oriented medially, coincident with the direction of movement in DMSO-treated embryos (A–A'''') but are oriented in all directions in LY-treated embryos (B–B''''). Rose (C) and bar (D) graphs displaying the orientation of membrane protrusions in DMSO- (left) or LY- (right) treated embryos. The length of each radial bar in (C) represents the percentage of protrusions in each bin. Bar graph displays the total percentage of forward or backward protrusions. Forward protrusions: 270–90°, pink. Backward protrusions: 90–270°, black. n = 425 protrusions from 11 cells in 5 embryos (DMSO), and 480 protrusions from 11 cells in 4 embryos (20 μM LY). Fisher’s exact test, p-value 1.8 × 10−5. Mean ± standard error. Scale bar, 30 μm. Raw data included in the source file.
Figure 4—source data 1. Statistical source data for quantification of myocardial protrusion properties.