|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 10, 387-418, Copyright © 1972 by Company of Biologists
Submitted on August 14, 1971
1 Department of Zoology, Cambridge University, England; Institute of Molecular Biology, Odense University, DK-5000 Odense, Denmark.
2 Virology Institute, University of Glasgow, Scotland; Department of Biology, Case Western Reserve University, Cleveland, Ohio 44106, U.S.A.
We have measured the concentrations of dry matter in mitotic apparatuses (MA) in vivo and after isolation from the same cell type. The isolation medium was hexylene glycol plus buffer. The MA were from sea-urchin zygotes (Echinus esculentus Linn. and Psammechinus miliaris Gmelin), and measurements were made using interference microscopy.
MA as isolated have much lower concentrations of dry matter than do MA in vivo. The dry mass concentrations of isolated MA vary with the pH of the isolation medium, ranging from about 20 % of the in vivo concentration (at pH 7.3) to about 60 % of the in vivo concentration (at pH 5.3).
The isolated MA were further characterized. Evidence is presented which suggests that non-specific cytoplasmic material adsorbs to MA, and thus that at least some of the material in isolated MA is not derived from in vivo MA. Some MA components are apparently changed during the isolation procedure: MA lysed in low pH (high mass) medium and quickly transferred to high pH (low mass) medium have higher concentrations of dry matter than do MA lysed in high pH medium.
The isolation media as generally used do not have enough buffering capacity: the pH changes after the isolation.
These data suggest that the isolation procedures need be improved before studies of isolated MA can give data relevant to the chemistry of in vivo MA. We discuss the problem of obtaining functional isolated MA, and also the relevance of our data to previous work on MA from other species.
Submitted on August 14, 1971
This article has been cited by other articles:
|
|
 |
|
  L. Du and S. L. Warren A Functional Interaction between the Carboxy-Terminal Domain of RNA Polymerase II and Pre-mRNA Splicing J. Cell Biol., January 13, 1997; 136(1): 5 - 18. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Kim, L. Du, D. B. Bregman, and S. L. Warren Splicing Factors Associate with Hyperphosphorylated RNA Polymerase II in the Absence of Pre-mRNA J. Cell Biol., January 13, 1997; 136(1): 19 - 28. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Maloff, S. Scordilis, and H Tedeschi Membrane potential of mitochondrial measured with microelectrodes Science, March 4, 1977; 195(4281): 898 - 900. [Abstract] [PDF]
|
|
