A rapid and convenient procedure for the detection of inhibitors of DNA synthesis using starfish oocytes and sea urchin embryos.

Abstract
A rapid and convenient procedure for the detection of inhibitors of DNA synthesis using starfish oocytes and sea urchin embryos at the 1-cell stage is described. The procedure is based on the findings that inhibitors of DNA synthesis block mitotic cell division of sea urchin embryos which requires DNA synthesis but do not affect meiotic maturational divisions of starfish oocytes which are independent of DNA synthesis. The efficacy of the method is verified by the isolation of aphidicolin, an inhibitor of DNA synthesis, from the culture filtrate of the fungus Harziella entomophila according to the bioassay procedure proposed in this study.