Cell fusion-impaired variants of a mouse lymphocytic cell line obtained by single-step selection for polyethylene glycol resistance.

This report describes an effective method for single-step isolation of cell line variants with reduced intercellular plasma membrane fusion ability. Variants, derived from a subline of L5178Y, were obtained by selection for growth in the presence of a toxic level of PEG 6000. These variants occurred after EMS treatment and spontaneously. Further testing revealed a pleiotropic phenotype, fusion impairment and polyethylene glycol resistance, which has been designated PgfR. Variant sublines, in serial subculture for more than 165 days on nonselective medium, retain a stable PgfR phenotype. PgfR variants have an approximate 7-fold reduction in intercellular fusion competence.