Increased polyethylene glycol-mediated fusion competence in mitotic cells of a mouse lymphoid cell line

Spontaneous mitotic cells of the mouse leukemic cell line GF7 are preferentially included in cell fusion products after treatment with polyethylene glycol (PEG). This implies a unique configuration of the natural mitotic membrane which is particularly vulnerable to induction of fusion by PEG. Colcemid-arrested GF7 mitotic cells, however, are excluded from PEG-induced cell fusion products, suggesting that colcemid reverses the membrane configuration which is susceptible to the action of PEG. When Sendai virus is used as the fusogenic agent, both colcemid-arrested and spontaneous mitotic cells are selectively fused. There must, therefore, be an essential membrane-fusogen reaction which is characteristically different for each of these agents.