The unicellular organism, Noctiluca, has been examined with the electron microscope. The nucleus is small compared to the very large size of the cell, but the nuclear border has an organization which indicates an active nucleocytoplasmic exchange. Whereas annuli are missing over most parts of the nuclear membrane proper, there are "annulated vesicles" in a layer inside the nuclear membrane. The hypothesis is put forth that nuclear substances move through the annuli into these vesicles, and that the annulated vesicles themselves are transported through the nuclear membrane. The various forms of the annulated vesicles are consistent with this hypothesis. An implication of this postulate is the synthesis of annulated membranes inside a closed nucleus which are physically separate from the endoplasmic reticulum. The chromosomes are in a state resembling prophase chromosomes and are surrounded by granular masses. Only a small portion of the entire nuclear volume is occupied by the chromosomes. There are many nucleolus-like bodies.
Article| October 01 1963
THE NUCLEUS OF NOCTILUCA SCINTILLANS : Aspects of Nucleocytoplasmic Exchanges and the Formation of Nuclear Membrane
Björn A. Afzelius
From The Wenner-Gren Institute, Stockholm, the Misaki Marine Biological Station, Misaki, Japan, and the Kristineberg Zoological Station, Sweden.
Dr. Afzelius' present address is The Wenner-Gren Institute, University of Stockholm, Stockholm, Sweden
Received: March 22 1963
Online ISSN: 1540-8140
Print ISSN: 0021-9525
Copyright © 1963 by The Rockefeller Institute Press
Björn A. Afzelius; THE NUCLEUS OF NOCTILUCA SCINTILLANS : Aspects of Nucleocytoplasmic Exchanges and the Formation of Nuclear Membrane . J Cell Biol 1 October 1963; 19 (1): 229–238. doi: https://doi.org/10.1083/jcb.19.1.229
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