Item – Thèses Canada

Numéro d'OCLC
1265421574
Lien(s) vers le texte intégral
Exemplaire de BAC
Auteur
Zannis-Hadjopoulos, Maria.
Titre
DNA synthesis in a purine auxotrophic mutant of Chinese hamster cells.
Diplôme
Doctor of Philosophy -- McGill University, 1979
Éditeur
[Montreal, Québec] : McGill University 1979
Description
1 online resource
Résumé
When V79 pur 1 cells are maintained in the absence of purines, the cells stop growing but remain viable for up to 48 h. Within the first 6 h after purine deprivation DNA synthesis is inhibited and the cells are arrested in S phase. The purine deoxyribonucleoside triphosphate (dNTP} pools decrease in size and the pyrimidine (dNTP) pools expand. Restoration of purine nucleotides into the medium results in normal rates of DNA synthesis both in vivo and in vitro. Kinetic analyses of DNA synthesis in samples pulsed for 1 min and chased for 1 h show a delay in maturation of newly replicated Okazaki-type pieces to full size DNA. DNA fiber autoradiography reveals a retardation in the rate of replication fork movement but no apparent inhibition of initiation in active clusters of replication units. The results indicate that purine deprivation upsets the intracellular dNTP pool balance and inhibits the elongation of nascent DNA chains.
Autre lien(s)
escholarship.mcgill.ca
escholarship.mcgill.ca
Sujet
Microbiology