Fig. 6

Fates of micromere 2d, and its subclones, during gastrulation and organogenesis. Images of live embryos, with dextran and diI-labeled 4d, 2d, or 2d 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–dd. a Dorso-lateral view of an early epiboly-stage embryo. Corresponding ventral views of embryos during epiboly are shown in b-c, d-e, f-g with different combinations of fluorescence and/or DIC layers shown. h, i Corresponding dorsal views of same embryo shown in f, g. Corresponding ventral view images of successively older embryos undergoing epiboly are shown in j-k, l-m. n, o Shows corresponding dorsal views of an embryo at the same stage as that shown in l, m. p Ventral surface view of an elongated embryo. q Ventral view of embryo undergoing elongation. Note unlabeled voids where the two terminal cells (tc) from 3c²²¹ and 3d²²¹ reside. r, s Corresponding ventral views of embryo undergoing elongation. t, u Right-lateral views of older embryo at the onset of organogenesis. v, w Corresponding left-lateral views of embryo at the onset of organogenesis. x, y Ventral views of embryo undergoing elongation. Unlabeled voids occupied by the two terminal cells (tc) are also indicated in x. Corresponding left-lateral (z, aa) and right-lateral/oblique (bb, cc) views of older embryos during organogenesis. dd Shows a ventral view of an embryo during organogenesis. pb polar body, ns neurosensory cell. Other labels are the same as those used in Figs. 3 and 4. Scale bar equals 50 μm