A gonial mitosis-stimulating factor in cerebral ganglia and hemolymph of the marine mussel Mytilus edulis L

Abstract A gonial mitosis-stimulating factor produced by the cerebral ganglia of the mussel Mytilus edulis has been demonstrated. This factor induces an increase of [ 3 H]thymidine incorporation in the DNA of isolated mantle cells. Dose-response data are obtained with the methanol phase of an acidic ganglia extract. The rate of [ 3 H]thymidine incorporation is compared with aspartate transcarbamylase specific activity, another bioassay previously described to estimate mitotic activity. This heat-stable mitogenic factor appears to have a molecular weight of less than 5000 Da. A gonial mitogenic factor is also found in the hemolymph and circulatory cells.