Karyotypic Changes in Mycoplasma-Modified Lines of FL Human Amnion Cells ∗

Abstract

Summary

Karyotypes of the mycoplasmainfected and -modified F 138 line of FL human amnion cells and of this line after mycoplasma elimination (F 138 cl) differ distinctly from karyotypes of FL cells. In the hypertriploid FL cells there is an increase in number of chromosomes in all groups as compared to the diploid cell (Denver classification). All FL metaphase plates contain a large submetacentric marker chromosome, sometimes in duplicate or triplicate, and two group C chromosomes with marked secondary constrictions. The hypotriploid F 138 and F 138 cl karyotypes differ from FL by containing fewer chromosomes in groups A, C, and D, but more chromosomes in group B; the two group C chromosomes with pronounced secondary constrictions are absent, but notable new chromosome varieties have appeared. The F 138 cl karyotypes contain lower number of chromosomes in groups E, F, and G, but higher numbers in group B than F 138 karyotypes. There is pronounced variation among karyotypes within each cell line. Attempts are made to correlate differences among karyotypes of the three cell lines to their differences in biological behavior in vitro and in vivo.