Fig. 8

Fig. 8 The NEM cell cluster is composed of a mixture of cells, some of which are connected to the YSL in oblong-stage embryos. In three different embryos (A and B, C and D, E and F), the yolk cell was loaded with Texas Red-dextran at the oblong stage of development. The embryos were then allowed to internalize SYTO-11 by endocytosis at dome stage. The embryos were observed at 70%-epiboly (A-D) or at 14-somite stage (E, F). The top row shows SYTO-11 labeling (A, C, E); the bottom row shows Texas Red-dextran labeling (B, D, F). (A, B) NEM/forerunner cells, labeled with SYTO-11, are located at the dorsal side of the blastoderm. Thick arrows point to cells that also contain Texas Red-dextran (see B). These cells are located near the YSL-EVL junction. Thin arrows point to SYTO-11 labeled NEM/forerunner cells that do not contain Texas Red-dextran (see B). This result indicates that SYTO-11 can accumulate in NEM/forerunner cells in the absence of a cytoplasmic connection to the YSL. (C, D) A different embryo shows a similar mixture of labeled and unlabeled cells. Thick arrows point to SYTO-11-labeled NEM/forerunner cells containing Texas Red-dextran. Thin arrows point to NEM/forerunner cells that do not contain Texas Red-dextran. (E, F) A 14-somite-stage embryo viewed from the side with Kupffer’s vesicle visible. The thick arrow points to a forerunner cell that contains Texas Red-dextran; the thin arrow points to a forerunner cell that is devoid of Texas Red-dextran.