Fig. S5

Further notch and somitic morphant data.

In order to show not all Notch ligand expression was affected in snai2 SB morphants, we analyzed aortic expression of dll4 and dlc by WISH at 26 hpf (A). SB morphants showed normal levels of both ligands supporting that the aorta is specified correctly. The presence of the Notch intracellular domain in Tg(UAS:NICD-myc) embryos can be assayed by immunohistochemistry for the myc tag, fused to the NICD. Representative images were taken of positive and negative staining present when the transgenic was crossed to the Tg(kdrl:miniGal4) (B). Staining is visible in the dorsal aorta and caudal vein, as well as quite strongly in the caudal hematopoietic tissue of Gal4⁺/NICD⁺ embryos. Double fluorescent in situ for dld and myoD was performed in SB morphants and their siblings at 14 hpf, and the results imaged by confocal microscopy (C). Representative images show that morphant embryos have decreased somitic dld staining, especially within the more anterior somites. myoD in the same somites was expressed normally. We also analyzed jam2a expression by WISH (D), since not only is this gene expressed within the somites, but it has been shown to be essential for notch signal transduction to the migrating PLM. SB morphants showed normal expression of jam2a. Numbers in the lower right-hand corner of each image depict the number of embryos with the phenotype pictured out of the total number of embryos assayed in each condition.