Fig. 2. The geniohyoideus is a hypaxial muscle and originates from the anterior trunk somites. DiI labeling (red) and 12/101 immunofluorescence (green) was used to track the migration of cells from the anterior trunk somites. (A) A schematic of the stage 28 injections [modified, with permission, from Niewkoop and Faber (Niewkoop and Faber, 1967)]. A live tadpole is visualized at stage 37 (B) and 45 (C). The original site of the injection is marked by an arrowhead, while labeled cells that have migrated into the head are marked with arrows. (C-G) Ventral views of the head. (D-G) The migratory population of cells coming from the anterior trunk somites co-localize with the geniohyoideus muscle at stage 45. A light-field image is shown in D, DiI labeling in E, 12/101 in F and the merge of the DiI and 12/101 images in G.