True protoplasts of the halophilic green alga Dunaliella peircei proven by electron micrograph were induced by treatment with pronase. They were fused with the spheroplasts of E. coli harboring P35S-CAT plasmids by polyethylene glycol(PEG) and calcium cations and then allowed to regenerate on selection media. Some Dunaliella-like clones were isolated from the media with acquired resistance to chloramphenicol appears to be the result of a genetic transfer from the plasmids harbored in E. coli. Moreover the c...