Fig. 6

Unexpected roles for extraembryonic Ndr2 and Ndr1 in mesoderm induction. (A-L) Live (A-C,G-I) and RNA-stained (D-F,J-L) phenotypes of pharyngula stage (24 hpf) WT zebrafish embryos, Zndr1 embryos and their sibling controls and MZoep embryos after YSL injection of Ctrl MO (A,D), Ndr2 MO (G,H,J,K), Ndr2 MO combined with the Ndr1 ATG MO reported by Fan et al. (Fan et al., 2007; Feldman and Stemple, 2001) (ZFIN ID: MO4-ndr1) (B,E), or Ndr2 MO combined with the Ndr1 MO reported by Gore et al. (Gore et al., 2005) (ZFIN ID: MO2-ndr1) (C,F). Embryos in J-L were fixed and stained with two antisense probes: egr2b, which encodes a zinc-finger transcription factor and labels hindbrain rhombomeres 3 and 5; and desma, which encodes the intermediate filament protein Desmin A and labels muscles in the heart, trunk somites and tail somites. Arrows point to the anterior limit of the tail; arrowheads point to heart muscle staining by desma and r3 and r5 indicate rhombomere 3 and 5 staining by egr2b. Fractions indicate the number of equivalent outcomes/number of embryos observed. Siblings of the embryos in C and F are also shown in Fig. 7E and 7G, respectively.