The molecular biology ofEuglena gracilis. XV. Recovery from centrifugation-induced stratification
✍ Scribed by Kempner, E. S. ;Miller, J. H.
- Book ID
- 102100301
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 345 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0886-1544
- DOI
- 10.1002/cm.10145
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✦ Synopsis
Abstract
The contents of Euglena gracilis cells can be separated in vivo by ultracentrifugation. Within the unbroken cell, each set of components forms a distinct layer according to their respective densities. The degree of segregation increases with both the g‐force and the time of centrifugation, up to a maximum at 100,000 × g for 1 h, when six distinct strata can be observed. When returned to normal growth conditions, essentially all the cells return to the normal state and growth pattern. Greater g‐forces or longer exposures do not alter the observable strata, but the ability of the cells to recover is diminished. Smaller g‐forces result in less separation of cellular contents and all cells recover, even after 18 h of exposure. Euglena cells stratified at 100,000 × g for 1 h were returned to normal growth conditions; recovery was followed microscopically and by the rate of utilization of oxygen as well as that of the single carbon source. The cells recovered their normal state within 1 to 2 h, which is only a tenth of the normal doubling time. The mechanism for this recovery involves a natural process of change in cell shape caused by contraction and relaxation of the pellicle, a cell surface structure. Cell Motil. Cytoskeleton 56:219–224, 2003. Published 2003 Wiley‐Liss, Inc.