Cell cycle exit timing

Timing cell-cycle exit and differentiation in oligodendrocyte development... 

The Xenopus system has proven instrumental in determining the mechanism controlling exit from mitosis at the metaphase/anaphase transition. Studies in this area have relied heavily on extracts prepared from fully mature oocytes/ unfertilized eggs that are arrested at metaphase of the second meiotic division. Upon Ca2+ addition, anaphase is initiated and the extract enters the first embryonic cell cycle to replicate DNA. The activity responsible for metaphase arrest was discovered by Masui at the same time as MPF (Masui Markert 1971), and given the name cytostatic factor (CSF). CSF has never been purified... 

Barres BA, Lazar MA, Raff MC 1994 A novel role for thyroid hormone, glucocorticoids and retinoic acid in timing oligodendrocyte development. Development 120 1097-1108 deNooij JC, Letendre MA, Hariharan IK 1996 A cyclin-dependent kinase inhibitor, Dacapo, is necessary for timely exit from the cell cycle during Drosophila embryogenesis. Cell 87 ... 

The binding of cisplatin to DNA is not in itself sufficient to cause cell death. Cells usually take several days to die after incubation with cisplatin, and it is during this time that decisions are made that impact on the survival or death of the cell. Cisplatin is generally considered a cell-cycle-phase non-specific drug, but it is still more toxic to dividing cells than to resting cells. Furthermore, cisplatin can be up to 10 times more toxic to cells that are about to enter S-phase than cells that have just exited S-phase. In one series of experiments, normal human fibroblasts were incubated with cisplatin while arrested at confluence at various times thereafter, they were analyzed for the amount of DNA-bound platinum, and plated to score cell... 

Cell cycle Is the repeated series of events In cells that lead to division of a parental cell Into tw/o daughter cells. The cell cycle Is divided Into Interphase and M phase. The Interphase encompasses the Gl phase (gap 1, cell growth), S phase (synthesis, DNA replication), G2 phase (gap 2, cell growth and preparation for mitosis). During the M phase, mitosis and cytokinesis take place. After completion of cell division, cells may enter the Gl phase for a next round ofcell division. Alternatively, cells may exit the cell cycle and remain in a resting state (also called GO phase). In this quiescent state, cells can remain for a long period of time or even indefinitely (Figure 1). 

When choosing a solar simulator for PEC research, one should carefully consider the orientation of the light exit port. Most solar simulators have their exit port oriented vertically, i.e., shining down. This is convenient for solid-state solar cells, but a bit of a hassle for PEC cells containing a liquid electrolyte -one would have to use a mirror since the photoelectrode is mounted vertically in most PEC cells. Fortunately, several manufacturers offer the possibility to have the light exit sideways. Some solar simulator manufacturers even offer integrated electromechanical shutters, with minimum exposure times as short as 200 ms and lifetimes >10 cycles. There are many manufacturers of solar simulators, and some well-known names include Oriel Instruments (Newport), Asahi, Abet Technologies, Luzchem, Wacom, Spire, Voss, etc. 

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