Cytoplasmic transfer of a determinant for chloramphenicol resistance between mammalian cell lines

Abstract

A genetic analysis of the resistance phenotype of a recently described chloramphenicol-resistant variant derived from the human cell line, HeLa [human cervical cancer] (MC63), has been undertaken. Whole cells or enucleated fragments, produced by treatment with cytochalasin B, were fused with chloramphenicol-sensitive mouse or human cells. Enucleated cells (cytoplasts) act as very efficient donors of the resistance phenotype in fusions with other human cell lines derived from HeLa. Chloramphenicol resistance is determined cytoplasmically. Transfer of resistance to unrelated human cell lines occurred at much lower frequency and transfer to mouse cells could not be demonstrated. An examination of mitochondrial protein synthesis in the fusion products of cytoplasts and whole cells suggested that mixed populations of mitochondria from both parental cells were maintained under the conditions of selection.