A Few Reminiscences About Nucleocytoplasmic Transport

Abstract

To be or not to be, that was the question for the nuclear membrane when I attended, in 1927, my first course in Cytology. For a majority of cytologists, the nucleus was surrounded by a mere film resulting from a precipitation between nuclear and cytoplasmic colloids; the membrane seen in fixed and stained preparations under the microscope was nothing but an artifact; its very existerce was doubtful. This is what I was taught by our teacher, this is what E.B. Wilson said in his famous treatise “The Cell in Development and Heredity” (1925). There was so little interest in the nuclear membrane that Wilson devoted less than one page to the topic. Nobody was interested, 60 years ago, in exchanges of molecules between the nucleus and the cytoplasm; nobody believed that, if such exchanges existed, they might be important for the cell. This overcautious attitude toward the nuclear membrane was due to the powerful influence of Jacques Loeb: in “The Dynamics of Living Matter” (1906), he wrote on p. 191: “the nucleus is surrounded by a solid film”. And on p.39, he corrected Traub who had been speaking of a cell membrane: he wrote in a footnote: “we should now say, the surface film of the protoplasm”.