RNA synthesis: a requirement for hormone-induced DNA amplification in Rhynchosciara americana
| Autor: | H.D. Berendes, Francisco Lara |
|---|---|
| Rok vydání: | 1975 |
| Předmět: |
DNA Replication
Ecdysone Time Factors Tritium Chromosomes Salivary Glands chemistry.chemical_compound Genetics medicine Animals Genetics (clinical) Salivary gland biology Diptera Dna amplification biology.organism_classification Molecular biology medicine.anatomical_structure Genes chemistry Larva Dactinomycin Autoradiography RNA Female Rhynchosciara americana Elongation Developmental biology DNA Thymidine Hormone |
| Zdroj: | Chromosoma. 50 |
| ISSN: | 1432-0886 0009-5915 |
| DOI: | 10.1007/bf00283470 |
| Popis: | Injection of beta-ecdysone into mid fourth instar larvae of Rhynchosciara americana induced within 23-28 hours after injection a rise in the percentage of 3H-thymidine (3H-TdR) incorporating nuclei in salivary gland region S1 from about 10-20% in the controls to 80-90% in the injected larvae. The 3H-TdR incorporating nuclei displayed a weak continuous labeling pattern or a band-labeling pattern with grains over the vast majority of the bands. The majority of nuclei with a band labeling pattern displayed DNA amplification at the DNA-puff regions.--Injection of actinomycin D at different times after ecdysone injection abolished the higher incorporation rate at the amplifying regions within 15 hours after the injection. However, the percentage of nuclei incorporating 3H-TdR and the frequency of the two labeling patterns remained essentially the same when RNA synthesis was inhibited. Only the over-all rate of 3H-TdR incorporation seemed to be reduced.--These data suggest that in the DNA puff regions the rate of DNA chain elongation is higher when amplification occurs than during a normal replication cycle. It, further, seems that the higher rate during amplification is dependent upon de novo RNA synthesis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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