Ultrastructural comparison between the distribution of concanavalin A and wheat germ agglutinin cell surface receptors of normal and transformed hamster and rat cell lines.

A comparative study on the distribution of concanavalin A and wheat germ agglutinin receptor sites is presented. Normal hamster cell cultures and an SV40-transformed hamster cell line were used, as were normal rat fibroblasts as well as rat cells transformed by polyoma virus, SV40 virus, and adenovirus 12. The localization of these two lectins on the cell surface is visualized in the electron microscope by means of ultrastructural cytochemistry based on the use of horseradish peroxidase as a marker. Two main facts are reported. FirsjU the pattern of WGA labeling of normal hamster cells and a cell line transformed by SV40 (C12TSV5) is similar to that previously shown for the same material with concanavalin A. Normal hamster cells tend to have a more regular surface reaction, while transformed cells frequently show a discontinuous label. These discon tinuities are believed to translate an increased mobility of lectin sites on the plasma membrane. Second, conversely, neither the concanavalin Anor the wheat germ agglutininperoxidase procedure allows one to distinguish normal rat cells from homologous cells transformed by polyoma virus, SV40 virus, or adenovirus 12. It is concluded that, even if the electron microscopic visualization of lectin receptors shows regular differences between normal and virus-transformed cells for a given cell system and the above-mentioned viruses, this observation cannot be generalized for other cells from different species and other transforming agents.