[Histoautoradiography of the DNA in trophoblast giant cells of the mouse placenta. A contribution to the problem of metabolic DNA].

The trophoblast giant cells of the mouse placenta are mitotically inactive. Nucleolar RNA synthesis is apparently at a standstill. The high nuclear DNA contents of these cells shown by 3H-thymidine marking is conceived by us to be a synthesis of metabolic nuclear DNA. Thus protein synthesis in trophoblast giant cells has been taken over by a metabolic DNA.