DNA replication in homogenates ofPhysarum polycephalum
| Autor: | E. N. Brewer, Pauline Ting |
|---|---|
| Rok vydání: | 1975 |
| Předmět: |
DNA Replication
Physiology Deoxyribonucleotides Clinical Biochemistry Spermine Physarum polycephalum Biology Cycloheximide Polyethylene Glycols Fungal Proteins Physarum chemistry.chemical_compound Adenosine Triphosphate Magnesium Myxomycetes Egtazic Acid Cell-Free System DNA synthesis Temperature DNA replication Cell Biology biology.organism_classification Kinetics Glucose chemistry Biochemistry Calcium Energy source DNA |
| Zdroj: | Journal of Cellular Physiology. 86:459-470 |
| ISSN: | 1097-4652 0021-9541 |
| DOI: | 10.1002/jcp.1040860304 |
| Popis: | Homogenates of Physarum polycephalum incorporate [3H]dATP into nuclear DNA at an initial rate of approximately 15% of the in vivo rate. To attain this level of synthesis, cultures, are homogenized in a medium containing Mg++, EGTA, glucose and spermine. Incorporation is strongly stimulated by the addition of ATP and all four deoxyribonucleoside triphosphates to homogenates prior to incubation. Various inorganic cations other than Mg++ either do not affect synthesis or are inhibitory. Incorporation is inhibited by a nonionic detergent, Triton X-100. DNA synthesis in this cell-free nuclear system is similar in several respects to that which occurs in vivo: (1) The rate of DNA synthesis in the intact organism at a given time in the mitotic cycle is reflected by the level of synthesis in homogenates prepared from cultures at that time of the cycle; (2) DNA strands labeled in vitro exhibit alkaline sucrose density gradient sedimentation properties similar to those of daughter-strand DNA pulse-labeled in vivo; and (3) Homogenates of cultures which were pre-treated with cycloheximide incorporate [3H]dATP at about 60% of the level observed in homogenates of untreated controls. |
| Databáze: | OpenAIRE |
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