![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
|
|
|
|
|
||
A more recent version of this article appeared on January 1, 2005
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on August 26, 2004
Revised on October 12, 2004
Accepted on October 13, 2004
*Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21210; Department of Biology, Johns Hopkins University, Baltimore, MD 21218
Monitoring Editor: J. Richard McIntosh
Nuclear organelles, unlike many cytoplasmic organelles, lack investing membranes, and are thus in direct contact with the surrounding nucleoplasm. Because the properties of the nucleoplasm and nuclear organelles influence the exchange of molecules from one compartment to another, it is important to understand their physical structure. We studied the density of the nucleoplasm and the density and permeability of nucleoli, Cajal bodies (CBs), and speckles in the Xenopus oocyte nucleus or germinal vesicle (GV). Refractive indices were measured by interferometry within intact GVs isolated in oil. The refractive indices were used to estimate protein concentrations for nucleoplasm (0.106 g/cm3), CBs (0.136 g/cm3), speckles (0.162 g/cm3), and the dense fibrillar region of nucleoli (0.215 g/cm3). We determined similar protein concentrations for nuclear organelles isolated in aqueous media, where they are no longer surrounded by nucleoplasm. To examine the permeability of nuclear organelles, we injected fluorescent dextrans of various molecular weights (3 kDa - 2000 kDa) into the cytoplasm or directly into the GV and measured the extent to which they penetrated the organelles. Together the interferometry and dextran penetration data show that organelles in the Xenopus GV have a low density, sponge-like structure that provides access to macromolecules from the nucleoplasm.
Present address: Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142.
Corresponding author.
E-mail: gall{at}ciwemb.edu
This article has been cited by other articles:
|
|
 |
|
  D. Grunwald, R. M. Martin, V. Buschmann, D. P. Bazett-Jones, H. Leonhardt, U. Kubitscheck, and M. C. Cardoso Probing Intranuclear Environments at the Single-Molecule Level Biophys. J., April 1, 2008; 94(7): 2847 - 2858. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Richter, M. Nessling, and P. Lichter Experimental evidence for the influence of molecular crowding on nuclear architecture J. Cell Sci., May 1, 2007; 120(9): 1673 - 1680. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Q. Xie, S. Martin, P. V. Guillot, D. L. Bentley, and A. Pombo Splicing Speckles Are Not Reservoirs of RNA Polymerase II, but Contain an Inactive Form, Phosphorylated on Serine2 Residues of the C-Terminal Domain Mol. Biol. Cell, April 1, 2006; 17(4): 1723 - 1733. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Sun, H. Xu, S. H. Subramony, and M. D. Hebert Interactions between Coilin and PIASy partially link Cajal bodies to PML bodies J. Cell Sci., November 1, 2005; 118(21): 4995 - 5003. [Abstract] [Full Text] [PDF]
|
|
