title: The exit of some human diploid fibroblasts (WI-38 cells) from the cell cycle in early G1.
abstract: The inducibility of DNA synthesis in WI-38 cells synchronized for different parts of G1 upon fusion with HeLa cells in S has been studied. In the heterokaryons 70 to 80% of WI-38 cell nuclei responded to HeLa inducers within one hour after cell fusion. The remainder of WI-38 cell nuclei responded to HeLa inducers after a lag of 3 hours or more. This lag was independent of duration of G1 traversed by WI-38 cells before cell fusion. The results of these studies suggest that 20 to 30% of WI-38 cells retire from the cell cycle in very early G1.
mesh_terms: D002460:Cell Line; D004261:DNA Replication; D005347:Fibroblasts / Q000166:cytology; D006367:HeLa Cells / Q000166:cytology; D006801:Humans; D007399:Interphase; D007700:Kinetics; D008677:Metaphase; D008940:Mitotic Index; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
chemical_list: D014316:Tritium; D013936:Thymidine