This material is from the 4th edition of The Zebrafish Book. The 5th edition is available in print and within the ZFIN Protocol Wiki. |
Fig 10. Formation of the yolk syncytial layer (YSL), viewed with Nomarski optics.
A: A marginal blastomere during the tenth interphase (512-cell stage; the arrow indicates its nucleus).
B: The nucleus disappears as the cell enters the tenth mitosis, a special one because there is no cytokinesis. The daughter nuclei then reappear in a common cytoplasm during interphase 11. During very early interphase the nuclei are globular (
C), and later, just before entering mitosis again they are large and football-shaped (
D). The YSL nuclei continue to disappear during mitoses (
E; mitosis 11; note that interphase nuclei are present just in the blastoderm cells and not the YSL, meaning that the blastoderm and YSL are no longer in synchrony,) and reappear during interphases (
F; interphase 12) for several mitotic cycles, always within a common syncytium. From Kimmel and Law (1985b). Scale bar: 50 µm.

Figure 10