Die auswirkungen der zellkern-entfernung auf die synthese von ribonukleinsäure und cytoplasma-proteinen bei Acetabularia mediterranea

Abstract

Resume In growing cells of the green unicellular and uninucleate alga Acetabularia mediterranea exist an equal linear increase of the quantity of RNA and soluble cytoplasmic proteins. By removal of the nucleus this relation between both processes is eliminated: net synthesis of the cytoplasmic RNA fraction ceases immediately which gives rise to a constant level of RNA in enucleated cells. On the other hand the amount of cytoplasmic soluble proteins increases until 21 days after enucleation. Enucleated fragments like anterior and posterior parts have no RNA net synthesis but they show an increase of their cytoplasmic proteins which ceases after 21 days. In nucleated fragments a strong synthesis of RNA and proteins occurs due to their ability of complete regeneration. During a dark period of 15–16 days the quantity of RNA decreases in nucleated and enucleated cells whereas the amount of cytoplasmic proteins remains constant. Following RNA and protein synthesis during re-illumination in these cells the results are not in contrast to those which were obtained with normal cultivated nucleated and enucleated cells. The results lead to the conclusion that the nucleus has an important role in the cytoplasmic net synthesis of RNA. But on the other hand the possibility of a nucleus independent synthesis of a small quantity of cytoplasmic RNA cannot be completely excluded.