Fusion of mycoplasmas: the formation of cell hybrids.

Poly(ethylene glycol) (PEG 8000) can induce cell-cell fusion of Mycoplasma capricolum cells, and it can promote the formation of intergeneric hybrids of various Mycoplasma, Acholeplasma and Spiroplasma species. The extent of fusion was quantitatively evaluated by following the dequenching of octadecylrhodamine fluorescent label incorporated into donor cell membranes after their incubation with recipient cells. The results of dequenching experiments were confirmed by electron microscopy, as well as by angle light-scattering measurements. Fusion appeared to require the presence of Mg2+, but was completely inhibited by either 0.1% glutaraldehyde or 100 microM chlorpromazine, and was partially suppressed by proteolytic enzymes, carbonyl cyanide-m-chlorophenylhydrazone, or thiol reagents.