| Autor: |
Wanka, F., Joosten, H., Grip, W. |
| Zdroj: |
Archiv für Mikrobiologie; Mar1970, Vol. 75 Issue 1, p25-36, 12p |
| Abstrakt: |
The composition and synthesis of DNA in synchronous cultures of Chlorella pyrenoidosa strain 211/8b has been investigated. Analytical CsCl density gradient centrifugation gave a homogenous major DNA component with a (G+C) content of 51% and a minor component containing 28% (G+C). The (G+C) contents derived from melting profiles were 2-3% lower. A second minor component with approximately 41% (G+C) content was inferred from banding patterns of labelled DNA in preparative CsCl density gradients. C-uracil was readily incorporated into the pyrimidine moieties of the major (nuclear) DNA between the 10th and 18th hour after beginning of the light period, but not at any other time. C-uracil incorporation into the minor (satellite) component was low but continuous throughout the whole cell cycle. The incorporation is correlated with an increase in the proportion of satellite DNA from 6% up to 20% during the time when no nuclear DNA replication takes place. The results suggest that different regulatory mechanisms exist for the nuclear and for satellite DNA synthesis. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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