Ultrastructure of hybrids derived from electric pulse fusion of human HeLa cells and murine 3T3.4E cells

Abstract

Somatic cell hybrids were obtained with electric pulse by fusion of human epithelial HeLa cells derived from uterine carcinoma and mouse fibroblasts 3T3.4E, deficient in thymidine kinase. Hybrids were selected and propagated in HAT medium. After 3 passages the cultures were morphologically homogeneous. They retained an epithelial morphology. Electron microscopic and morphometric studies indicate that these hybrids at the 6th passage differed from parental cells. They exhibited the smallest cellular and cytoplasmic size. The number of mitochondria was similar to that of murine fibroblasts but their size was more homogeneously distributed; the mitochondria matrix was more electron dense than in the parental cells. These data suggest that these hybrids have a different metabolism from that of the parental cells; they contained modified mitochondria.