Unilateral Cleavage Furrows in Multinucleate Cells

Abstract

Multinucleate cells can be produced in Dictyostelium by electric-pulse induced fusion. In these cells unilateral cleavage furrows are formed at spaces between areas that are controlled by aster microtubules. A peculiarity of unilateral cleavage furrows is their propensity to join laterally with other furrows into rings to form constrictions. This means, cytokinesis is biphasic in multinucleate cells, the final abscission of daughter cells being independent of the initial direction of furrow progression. Myosin-II and the actin-filament cross-linking protein cortexillin accumulate in the unilateral furrows, as they do in the normal cleavage furrows of mononucleate cells. Myosin-II is not essential for cytokinesis, but stabilizes and confines the position of the cleavage furrows.

Patterning of the cell cortex and the localization of cleavage furrows in multi-nucleate cells

“…In multi-nucleate wild-type cells of Dictyostelium discoideum produced by electric-pulse induced cell fusion, unilateral furrows are formed that by merging divide the cell body into multiple portions (Bindl et al, 2020). These data indicate that the mechanism of mitotic cleavage enables a cell to divide not only by a contractile ring (Satterwhite and Pollard, 1992) but also by the unilateral ingression of a furrow.…”

“…For the expression of fluorescent proteins in Septase-null mutant (Müller-Taubenberger et al, 2009) derived from the AX2-214 strain of Dictyostelium discoideum, cells were transfected with vectors encoding GFP-myosin II (Robinson et al, 2002), GFP-cortexillin I (Weber et al, 1999) pDRH-Hyg R :RFP-α-tubulin (Effler et al, 2006), GFP-α-tubulin (Neujahr et al, 1998), mRFP1histone 2B (Bindl et al, 2020), or mRFPM-LimEΔ (Fischer et al, 2004). The dual fluorescent labeled strains and combinations of selection markers used are displayed in supplemental Table S1.…”