Zygotic expression of the pebble locus is required for cytokinesis during the postblastoderm mitoses of Drosophila

• DOI: 10.1242/dev.114.1.165
• Publication Date: 2021-04-23T18:26:24Z
• Authors: Gary Hime; Robert Saint
• Keywords: Cell Nucleus; 0301 basic medicine; 0303 health sciences; Zygote; Gene Expression; Mitosis; Spindle Apparatus; 03 medical and health sciences; Microscopy, Fluorescence; Cell Movement; Mutation; Morphogenesis; Animals; Drosophila

ABSTRACT Mutations at the pebble locus of Drosophila melanogaster result in embryonic lethality. Examination of homo-zygous mutant embryos at the end of embryogenesis revealed the presence of fewer and larger cells which contained enlarged nuclei. Characterization of the embryonic cell cycles using DAPI, propidium iodide, anti-tubulin and anti-spectrin staining showed that the first thirteen rapid syncytial nuclear divisions proceeded normally in pebble mutant embryos. Following cellular-ization, the postblastoderm nuclear divisions occurred (mitoses 14, 15 and 16), but cytokinesis was never observed. Multinucleate cells and duplicate mitotic figures were seen within single cells at the time of the cycle 15 mitoses. We conclude that zygotic expression of the pebble gene is required for cytokinesis following cellularization during Drosophila embryogenesis. We postulate that developmental regulation of zygotic transcription of the pebble gene is a consequence of the transition from syncytial to cellular mitoses during cycle 14 of embryogenesis.