Molecular and Cell Biology of Cell Cycle Progression Revealed by Mammalian Cells Temperature-Sensitive in DNA Synthesis

Mouse Polyoma Virus and Adenovirus Replication in Mouse Cells Temperature-Sensitive in DNA Synthesis

“…Both gene products are required for semiconservative DNA replication, which occurs normally during the DNA-synthetic, or S, phase of the cell duplication cycle [3,5,11,12,24], Because they arrest at unique stages early in S phase, they are designated DNA'7S'\ The is 2 mouse fibroblast arrests at the Gi/S interface [28] upon temperature inactivation of a polypeptide which acts to effect S-phase entry, perhaps by facilitating interaction of DNA polymerase-a and DNA primase [27]. The ts2 cell is therefore DNA'1/ Gi'1 [3,5,28].…”

“…Both gene products are required for semiconservative DNA replication, which occurs normally during the DNA-synthetic, or S, phase of the cell duplication cycle [3,5,11,12,24], Because they arrest at unique stages early in S phase, they are designated DNA'7S'\ The is 2 mouse fibroblast arrests at the Gi/S interface [28] upon temperature inactivation of a polypeptide which acts to effect S-phase entry, perhaps by facilitating interaction of DNA polymerase-a and DNA primase [27]. The ts2 cell is therefore DNA'1/ Gi'1 [3,5,28]. These three ts gene products play no obligatory role in DNA repair repli cation [11,29], On the basis of these considerations and the data presented here it could be concluded that replication of mouse adenovirus DNA can occur in the absence of normal, semicon servative cellular DNA synthesis and does not require the participation of functional cellular DNA topoisomerase II orthe /.sCI or Is 2 gene products.…”