Timing of initiation of chromosome replication in individual Escherichia coli cells.

摘要: Abstract The synchrony of initiation chromosome replication at multiple origins within individual Escherichia coli cells was studied by a novel method. Initiation inhibited with rifampicin or chloramphenicol and after completion ongoing rounds the numbers fully replicated chromosomes in were measured flow cytometry. In rapidly growing cultures, parallel several chromosomes, will end up 2n (n = 1, 2, 3) if occurs simultaneously all origins. A culture asynchronous may addition contain irregular (not equal to 2n) chromosomes. The frequency is measure degree asynchrony initiation. After inhibition run-out B/r K-12 small fraction (2-7%) contained 3, 5, 6 7 From these measurements it calculated that four single cell occurred fraction, 0.1, doubling time (tau). dnaA(Ts) mutant strain grown permissive temperature exhibited very large drug treatment demonstrating virtually random timing similar pattern number per found recA strain.