CANCELING EFFECT OF 2, 4-DINITROPHENOL ON THE VEGETALIZATION OF SEA URCHIN LARVAE INDUCED WITH CAFFEINE

The treatment of the sea urchin morulae with both caffeine and 2, 4-dinitrophenol (DNP) for a couple of hours exerts no harmful effect on the development of sea urchin, whereas the tretment with caffeine alone yields vegetalized larvae. As long as the morulae are kept in the pressence of DNP alone, further development or the embryos is arrested, but the treated embryos develop normally after they are transferred into plain sea water. Hence, DNP is supposed to cancel vegetalizing effect of caffeine on the sea urchin morulae. When the embryos were kept in sea water containing respective radioactive precursors of macromolecules and caffeine, the radioactivity in the DNA fraction is slightly higher and those in the RNA and protein fraction are slightly lower than those of control ones (without the caffeine treatment). In the presence of DNP, the radioactivity in these macromolecules is very low in the caffeine-treated embroyos as well as in the control.