Bacterial checkpoints, analogous to those proposed to exist in eukaryotic cells, offer insights into the definition of a checkpoint. Examination of bacterial “checkpoint” or arrest phenomena illustrate problems with a too‐casual application of the checkpoint idea to eukaryotic phenomena. The question raised here is whether there are cellular processes that “check” whether a cellular process is completed. It is possible that many eukaryotic “checkpoints” may not have “checking” functions. Some of the ubiquitous checkpoint phenomena widely described may be merely the (...) result of the inherent incompleteness of earlier events preventing the initiation of subsequent events. BioEssays 28: 1035–1039, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

Bacterial checkpoints, analogous to those proposed to exist in eukaryotic cells, offer insights into the definition of a checkpoint. Examination of bacterial “checkpoint” or arrest phenomena illustrate problems with a too‐casual application of the checkpoint idea to eukaryotic phenomena. The question raised here is whether there are cellular processes that “check” whether a cellular process is completed. It is possible that many eukaryotic “checkpoints” may not have “checking” functions. Some of the ubiquitous checkpoint phenomena widely described may be merely the (...) result of the inherent incompleteness of earlier events preventing the initiation of subsequent events. BioEssays 28: 1035–1039, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

A eukaryotic “baby machine” has been developed that produces synchronized cultures that display up to four synchronous cell cycles. 1 That such cells can be produced implies that methods unable to produce successive synchronized cell cycles may not actually synchronize cells. But most important, the baby machine method now opens the way for the study of the cell cycle of minimally disturbed, artifact‐free, well‐synchronized, mammalian cells. BioEssays 24:499–501, 2002. © 2002 Wiley Periodicals, Inc.

The Schaechter–Maaløe–Kjeldgaard papers, which have their 50th anniversary this year, have major implications for understanding the cell cycle, control of cell growth, control of cell size, metabolic control, the basic bacterial growth curve, and myriad other bacterial and eukaryotic growth phenomena. These ideas have broad applications that should be considered in current studies of the cell cycle. In particular, the emphasis on steady‐state growth conditions, and clear and sharp changes in growth conditions were fundamental to their experiments and have been (...) codified in the principles of the Copenhagen School of Microbiology. BioEssays 30:1019–1024, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

It is widely accepted that there exists a “resting” or “quiescent” state where a growing cell leaves the cell cycle to enter what is often called the “G0‐phase.” I propose that there is no biological reality to the “G0‐phase.” The experimental basis for proposing a G0‐phase is re‐examined and re‐analyzed here showing that the G0‐phase is an anthropomorphic construct with no biological reality.