Fig. 7. Model of myocardial morphogenesis. The spatial organization of myocardial chamber progenitors at 40% epiboly and the locations of their progeny at tailbud and mid-somitogenesis stages suggest orderly migration of these populations. (A-I) Schematic representations of zones containing ventricular myocardial progenitors (red) or atrial myocardial progenitors (yellow). Zones containing both ventricular and atrial progenitors are depicted in red and yellow stripes. (A) Representation of myocardial fate map at 40% epiboly; primary data shown in Fig. 2B. (B-F) Frames from an animated model of myocardial morphogenesis (see Movie 1 at http://dev.biologists.org/supplemental); lateral views, dorsal towards the right, at (B) 40% epiboly, (C) shield, (D) 70% epiboly, (E) 85% epiboly and (F) tailbud stages. Background images adapted, with permission, from Karlstrom and Kane (Karlstrom and Kane, 1996). (G-I) Dorsal views, anterior towards the top, depicting myocardial progenitor zones within the LPM at (G) 5 somites, (H) 15 somites and (I) 22 somites.