Coexpression of nrarp-a and deltaC expression in the zebrafish presomitic mesoderm (PSM). A1-G2: Fluorescent double in situ hybridization was performed with (A1-G1) Cy3-thyramide substrate to visualize deltaC and then (A2-G2) fluorescein-thyramide substrate to visualize nrarp-a in the PSM of zebrafish embryos at the 10-somite stage. A3-G3: Merge of the two stainings to show that the progression of their expression along the PSM is simultaneous and the major difference in their pattern of expression is due to the longer half life of nrarp-a transcripts. Rostral to the top.

Nrarp expression is Notch-dependent in fish, chick, and mouse, but Wnt-dependent only in mouse. A-D: Hamburger and Hamilton (HH) stage 11-12 chick (A,C) and embryonic day (E) 9.5 (B,D) half embryo culture analysis. Both sides were cultured with or without (A,B) 100 μM DAPT to inhibit the Notch activity or (C,D) 200 μM CKI-7 to inhibit the Wnt activity. Both half explants were hybridized with an Nrarp probe. E-I: nrarp-a expression analyzed in the PSM of 10-somite stage zebrafish embryos from (E) wild-type (F) aei/deltaD mutant, and (G) des/notch1a mutant. Zebrafish embryos stained for nrarp-a expression after being incubated in the (H) absence or (I) presence of 200 μM CKI-7 to inhibit Wnt activity. Rostral to the top.

Gain and Loss of Nrarp function do not affect cyclic gene expression. A-F: Electroporated embryos incubated overnight after electroporation with control pCIG (A,D), pCIG-Nrarp (B,E), or pRFPRNAiC-Nrarp(A+B) (C,F), and analyzed by in situ hybridization for cLfng (A-C) and cHairy2 (D-F) expression in the presomitic mesoderm (PSM). G-I: Zebrafish embryos at the 10-somite stage after being incubated (G) without treatment (G) or after treatment (H,I) with nrarp-a and nrarp-b morpholinos and then analyzed by in situ hybridization for her1 expression in the PSM. J-M: E9.5 Nrarp-/- mice embryos analyzed by in situ hybridization for mLfng (J,K) and mHes7 (L,M) expression in the PSM. Rostral to the top.