Comparison of cellular effects of phomopsin and colcemid in Chinese hamster cells in vitro

The effects of the fungal toxin phomopsin A, which produces the disease lupinosis in farm animals fed on lupins infected with Phomopsis leptostromiformis, were studied in cultures of Chinese hamster cells. The results show that phomopsin A inhibits proliferation by blocking cells in metaphase, but that higher concentrations are needed than for colcemid, another mitotic poison. As with colcemid, there is an increase in both micronuclei formation and DNA synthesis. Unlike colcemid, phomopsin is also clastogenic.