Fig. 3. Cx38 was not essential for either normal development or GJIC in the early embryo. Oocytes were injected with sense or antisense oligo-1, capacitated by host-transfer and fertilized. Dye transfer was assessed at the 32-64 cell stage. (A) Both sense and antisense injected oocytes developed into grossly normal swimming tadpoles. (B) Northern blotting confirmed the elimination of Cx38 mRNA from the embryos by oligo-1. (C-J) A mixture of neurobiotin (red) and fluorescein-dextran (green) was injected into one animal cell at the 32-64 cell stage. After fixation and sectioning, GJIC is evident (stars) in blastomeres that contain neurobiotin but not fluorescein-dextran. Bar (C), 200 µm.