Fig. 4. Vegetal, cortical targeting of GFP-tagged LvDsh. (A) Fertilized egg. LvDsh-GFP (wild-type) targeted to one pole of the fertilized egg even before first cleavage (arrow). (B) Two-cell stage. The first cleavage plane bisected the zone of cortically localized LvDsh-GFP (arrow). (C) 4-cell stage. (D) 8-cell stage. LvDsh-GFP was concentrated in the vegetal cortex of the four vegetal blastomeres (arrow), which were slightly smaller than the four animal blastomeres. (E) 16-cell stage. The region of cortically localized LvDsh-GFP was inherited by the micromeres (arrow) and, to a lesser extent, the overlying macromeres. (F) High magnification view of the vegetal cortical region of vegetal blastomeres at the 8-cell stage, showing the punctate nature of GFP fluorescence (arrow). All panels show different embryos and all show lateral views except (C), which is viewed along the A-V axis.