Fig. 7

In the absence of the fin bud, the second migratory stream contributes exclusively to the PHM. (A-D) Confocal projections of six1b:lyn-GFP (green) and mylpfa:mCherry (magenta) transgene expression in embryos fixed at 36 or 48 hpf. These embryos were treated either with DMSO (control; A,C) or SU5402 (B,D) from 24 to 36 hpf. (E) Box plots of PHM length in control or SU5402-treated embryos, fixed at 48 hpf, showing that the PHM expands upon Fgfr inhibition. Asterisks indicate significant differences (P<0.01), determined by Tukey–Kramer HSD comparisons after one-way ANOVA. Measurements were obtained from 15 control embryos and 10 inhibitor-treated embryos for each experimental condition. See Materials and Methods for statistical details. (F,G) Similar to Fgfr chemical inhibition, dnFgfr induction (at 24 hpf) results in an initially expanded PHM stream. (H,I) By 72 hpf, the PHM in control wild-type embryos is larger than in dnFgfr-induced embryos. Arrowheads are color-coded as described in Fig. 1 legend. Scale bars: 100 µm.