KARYOLOGICAL AND MORPHOLOGICAL CHARACTERISTICS OF HUMAN DIPLOID CELL STRAIN WI-38 INFECTED WITH MYCOPLASMAS

It is clear that a number of strains of mycoplasmas are able to infect HDCS WI-38 causing high frequencies of chromosome breaks, which are not always accompanied by cytopathic degeneration. In one instance the frequency of breaks persisted in the apparent presence of low numbers of mycoplasmas. The addition of aureomycin to the medium eliminated the mycoplasmas and reduced the level of chromosome breaks to that of the control cultures. A most interesting observation was the appearance of leopard" cells (nuclei with clumped chromatin) in the infected cultures. It is suggested that the appearance of these nuclei may be associated with the interference of DNA synthesis of the host cells and an indication of the induction of chromosomal aberrations by mycoplasmas. © 1969."