(a–f) Single plane confocal images of two-color FISH for fgfr1 (a), dlc (b) and merged comparison (c), and fgfr4 (d), dlc (e) and their merged comparison (f) at 15 hpf. Yellow arrows indicate expressions of fgfr1 (a) or fgfr4 (d) in the somites. (g–u) Expression of somitic dlc at 15 hpf. (g–i), runx1 at 26 hpf (j–l), cmyb at 36 hpf (m–o), the endothelium marker kdrl (p–r), and the aortic marker efnb2a (s–u) at 26 hpf in fgfr4-MO2 injected embryos, compared to uninjected and mismatched control MO (fgfr4-CoMO) injected siblings. (v–x) Double-positive HSCs (white arrowheads) in kdrl:RFP; cmyb:EGFP transgenics in the fgfr4 morphants (x) compared to uninjected (v) and mismatched control MO injected (w) controls. (y) Quantitation of 50 hpf cmyb+
kdrl+ double positive HSCs in the DA of fgfr4 morphants (v–x) (uninj, n=5; control MO, n=5; fgfr4 morphants, n=9; *P-value < 0.01, significantly different from uninj and control MO injected ones, Student’s t-test). Scale bars=100μm.