|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 2, 151-162, Copyright © 1967 by Company of Biologists
Submitted on November 4, 1966
1 Department of Anatomy, Harvard Medical School, Boston, Massachusetts, U.S.A.
2 Department of Zoology, Oxford University
Mutant and normal Xenopus laevis embryos (0-nu, 1-nu, 2-nu) were examined in the electron microscope after glutaraldehyde and/or osmium-tetroxide fixation. During cleavage both 0-nu and wild-type embryos contain multiple small nucleolar bodies, less than 1 µ in diameter, composed mainly of a fibrous material. By the end of cleavage or beginning of gastrulation, granular caps develop on the fibrous nucleolar bodies. In 1-and 2-nu cells, the multiple nucleolar bodies are replaced during gastrula and neurula stages by definitive nucleoli (2-5 µ in diameter) which contain abundant small (150 Å) granules intermingled with fibrous material. In 0-nu cells, one or two pseudonucleoli (1-3 µ in diameter) appear at about the same time that definitive nucleoli develop in wild-type cells. The multiple small nucleolar bodies disappear as the pseudonucleoli enlarge. Pseudonucleoli differ from definitive nucleoli in having a much smaller amount of the granular component, which is located as a cap on the periphery of the fibrous component and not mingled with it. The granular component of the 0-nu pseudonucleoli, however, is not distinguishable in its fine structure from the same component of normal nucleoli. In many 0-nu tadpoles at stage 41, the granular component of the nucleolus is entirely absent and the fibrillar component is very prominent. Both granular and fibrous components of the 0-nu pseudonucleoli contain RNA as judged by RNase sensitivity and staining affinity for basic dyes.
Submitted on November 4, 1966
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Kneissel, W. W. Franke, J. G. Gall, H. Heid, S. Reidenbach, M. Schnolzer, H. Spring, H. Zentgraf, and M. S. Schmidt-Zachmann A Novel Karyoskeletal Protein: Characterization of Protein NO145, the Major Component of Nucleolar Cortical Skeleton in Xenopus Oocytes Mol. Biol. Cell, December 1, 2001; 12(12): 3904 - 3918. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Verheggen, S. Le Panse, G. Almouzni, and D. Hernandez-Verdun Presence of Pre-rRNAs before Activation of Polymerase I Transcription in the Building Process of Nucleoli during Early Development of Xenopus laevis J. Cell Biol., September 7, 1998; 142(5): 1167 - 1180. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P Bell, C Mais, B McStay, and U Scheer Association of the nucleolar transcription factor UBF with the transcriptionally inactive rRNA genes of pronuclei and early Xenopus embryos J. Cell Sci., January 9, 1997; 110(17): 2053 - 2063. [Abstract] [PDF]
|
|
|
|
|
|
C Cairns and B McStay Identification and cDNA cloning of a Xenopus nucleolar phosphoprotein, xNopp180, that is the homolog of the rat nucleolar protein Nopp140 J. Cell Sci., January 10, 1995; 108(10): 3339 - 3347. [Abstract] [PDF]
|
|
|
|
|
|
M. Azum-Gelade, J Noaillac-Depeyre, M Caizergues-Ferrer, and N Gas Cell cycle redistribution of U3 snRNA and fibrillarin. Presence in the cytoplasmic nucleolus remnant and in the prenucleolar bodies at telophase J. Cell Sci., January 2, 1994; 107(2): 463 - 475. [Abstract] [PDF]
|
|
|
|
 |
|
 Z. Wu, C. Murphy, C.-H.H. Wu, A. Tsvetkov, and J.G. Gall Snurposomes and Coiled Bodies Cold Spring Harb Symp Quant Biol, January 1, 1993; 58(0): 747 - 754. [Abstract] [PDF]
|
|
|
|
 |
|
 M Caizergues-Ferrer, P Mariottini, C Curie, B Lapeyre, N Gas, F Amalric, and F Amaldi Nucleolin from Xenopus laevis: cDNA cloning and expression during development. Genes & Dev., March 1, 1989; 3(3): 324 - 333. [Abstract] [PDF]
|
|
|
|
 |
|
 C. P. Emerson Jr. and T. Humphreys Ribosomal RNA Synthesis and the Multiple, Atypical Nucleoli in Cleaving Embryos Science, March 5, 1971; 171(3974): 898 - 901. [Abstract] [PDF]
|
|
