Figure 3—figure supplement 2.

Figure 3—figure supplement 2. Phosphoinositide 3-kinase (PI3K) signaling directs myocardial movement during the early stages of cardiac fusion and regulates velocity along the medial-lateral axis.

(A, B) Time-lapse confocal reconstructions from Figure 3 overlaid with cell movement tracks, starting at t = 0 (yellow dots). Graphs of average speed (C) and direction of movement (D) subdivided into three distinct stages of cardiac fusion: early movement (0–48min), posterior fusion (49–99min), and anterior fusion (100–153min). Graphs of average absolute medial–lateral velocity (E) and average absolute angular velocity (F) sub-divided into cells at the top, middle, and bottom of the myocardial populations. The average speed of myocardial cells in LY-treated embryos is consistently slower than DMSO-treated embryos (C). This defect appears to derive mostly from differences in medial-lateral movement (E) rather than in angular movement (F). In LY-treated embryos, myocardial cells display a more angular average direction of movement compared to DMSO-treated embryos during the early stage of cardiac fusion (early movement), after which wild-type myocardial cell movement becomes more angular matching myocardial cell movements in LY-treated embryos (D). Gray dots – individual cells, color squares – average per embryo. Average and standard error based on embryos. Scale bar, 60μm. Letter change indicates p < 0.05, one-way analysis of variance (ANOVA) (C, D, F) or t-test (E). Raw data and full p-values included in the source file.