when arrested heat- or cold-sensitive mutant cells were returned to the permissive temperature , ribonucleotide reductase activities , similar to dna polymerase alpha and to thymidine kinase in heat-sensitive mutants , increased essentially in parallel with reentry of cells into s phase , whereas the increase in thymidine kinase activity in the cold-sensitive mutants was previously shown to occur approx . one cell-cycle time later .
C0007634
cells
C0080129
into