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Cell Biology International (1993) 17, 1033–1038 (Printed in Great Britain)
Helical inclusions with nucleopore-like characteristics in the cytoplasm of swiss 3T3 Cells: A preliminary communication.
Denys N. Wheatley
Cell Pathology Laboratory, University Medical School, Foresterhill, Aberdeen AB9 2ZD, Scotland, U.K.


Helical inclusions have been observed at sites remote from the nucleus in the cytoplasm of Swiss 3T3 fibroblasts. Because of the interest shown in their unusual nucleopore complex-like nature, this preliminary communication briefly reports their existence and describes their essential ultrastructural features. Although they could be found singly, most formed collections of up to about 30 inclusions in which different planes of section were represented. TS profiles with hexagonal packing showed apparently identical eight-fold symmetry and dimensions to pores in the nuclear envelope of 3T3 cells. No membranes were associated with the inclusions, nor was there any suggestion of the strict vertical plate-like stacking found in annulate lamellae (AL). Furthermore, the inclusions were undoubtedly helical, and in all probability composed of several strands.

Key words: cytoplasmic inclusions - helices - 3T3 cells - annulate lamellae - nucleopores - polyribosomes.


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)