Cytoplasmic Protrusions in Insect Cells during Mitosis in Vitro

The formation of transient cytoplasmic protrusions, so called "bubbling," has frequently been observed in a number of living vertebrate cells since the early description of it in salamander epithelium by Peremeschko (1879). In cultured vertebrate cells, this phenomenon has been observed occasionally during mitosis (Strangeways, 1922; Boss, 1955). Hughes (1950) reported increased bubbling during artificially delayed anaphase. In vertebrates, Novikoff (1939) reported bubbling of Sabellaria eggs, and Baumgartner (1933) observed it in grasshopper and cricket spermatocytes. Chambers (1938) studied the induction of blebs in relation to cell injury. In the past, the reports have described protrusions of the cell surface mainly during late anaphase and telophase or at the time of cytokinesis. Surface bubbling of invertebrate cells in continuous culture in vitro has not been reported up to now. The present paper describes observations on dividing leafhopper cells in vitro.