Fig. 7
Fates of micromere 3a, and its subclones, during gastrulation and organogenesis. Images of live embryos, with dextran and diI-labeled 4d, 3a, or 3a subclones, as indicated. In some cases, the zygote was previously injected with mRNAs coding for fluorescent fusion proteins for histone H2B-RFP (H2B) and/or the actin-binding domain of utrophin-GFP (UTPH) to visualize nuclei or cell outlines, respectively, where indicated. Animal pole is up in a. Anterior is up in b–o. a Dorso-lateral view of an early epiboly-stage embryo. b Ventral (vegetal) view of early epiboly-stage embryo. c-d, e-f Show corresponding ventral views of early and mid epiboly-staged embryos, respectively, with different combinations of fluorescence and/or DIC layers shown. g, h Corresponding ventral views of later stage embryos undergoing epiboly. i Ventral view of an older, elongating embryo. j, k Ventral views of two embryos just prior to the onset of organogenesis. Note that for the original stack of confocal images shown as a projection in j, the 3a1 and 3a2 clones are spatially separated in the Z axis, making it possible to pseudocolor them separately, as labeled. Corresponding ventral views of embryo just prior to the onset of organogenesis are shown in l, m, n, o Left-lateral view of an embryo during organogenesis. cb ciliary band, ms mesenchyme. Other labels are the same as those used in Figs. 3 and 6. Scale bar equals 50μm