|
Fig. 6 S1pr2 is required for efficient convergence and extension movements of the anterior endoderm. Epifluorescence time-lapse experiments performed on Tg(sox17:EGFP) control (A-C) and mil mutant (E,F) embryos from the 5- to 10-somite stages (supplementary material Movies 3, 4). (A,D) Still images at the 5-somite stage. (B,E) Still image at the 10-somite stage, with the migration tracks of endodermal cells from the 5- to 10-somite stage superimposed. (C,F) Representative tracks delineate routes of the two populations of anterior endodermal cells (yellow is the anterior group, cells migrate anteriorly; green is the posterior group, cells migrate dorsally). (G,H) Total, net anterior (extension) and net dorsal (convergence) migration velocity of the anterior- and posterior-group endodermal cells in wild-type and mil mutant embryos. Data are mean±s.e.m. (G′,H′) Direction of cell migration throughout the time-lapse period (5-minute intervals), shown as the percentage of cells in 30° sectors. *P<0.05 versus control; **P<0.01. Scale bar: 100 μm.