Fig. 5. svp mRNA and protein expression in early NB7-3 lineage development. Embryos are double labelled for the NB7-3 lineage marker Eg (magenta), and svp mRNA (green) or Svp protein (green), as indicated. NB7-3-derived cells are outlined; midline is towards left. (A-D) svp mRNA expression in wild type. NB7-3 initiates svp expression before its first division (A). After this division, svp mRNA can be detected only in the NB (B) or in both cells (C). After the second NB division there is no detectable mRNA in most cases (D). (E-G) svp mRNA expression in pros^C7. As in wild type, NB7-3 expresses svp mRNA before the first division takes place (E). After this division, both cells are usually positive for svp mRNA, although the amount of transcripts in GMCa seems to be generally lower than in the NB (F). After the second NB division there is still detectable svp mRNA in GMCa in most cases (G). (H-J) Svp protein expression in wild type. There is only a little or no protein in NB7-3 prior to the first mitosis (H). After division, both cells are Svp⁺ (I). After the birth of GMCb, all cells are Svp⁺ but the highest amount of Svp protein is found in GMCa (J). (K-M) Svp protein expression in pros^C7 is similar to wild type. Scale bar: 20 µm.