Cell cycle regulation
Newport JW, Kirschner MW
Regulation of the cell cycle during early Xenopus development.
Cell 37: 731-742, 1984

The topic of this session is "cell cycle." The paper that we are going to discuss on November 5th was published in 1984, when the molecular players or regulatory mechanisms of the cell cycle were still largely a mystery. In the early 1980s, a partially purified activity named "maturation-promoting factor (MPF)," which had initially been regarded simply as an oocyte maturation (meiosis) inducer, was beginning to emerge as a candidate M-phase inducer. The activity of MPF appeared to oscillate in the fertilized (or activated) Xenopus egg, correlating with the intrinscic oscillatory properties that were maintained even without the cell nucleus. There was also an activity in the unfertilized egg cytoplasm named "cytostatic factor (CSF)," which caused metaphase arrest upon injection into cleaving Xenopus eggs. Their precise roles, however, were far from being fully understood. Furthermore, unlike the present era, molecular biology approaches were still very limited in those days, so elucidating the roles of MPF and CSF in detail was very challenging. Under such circumstances, what can a cell cycle researcher do toward understanding cell cycle regulation?

As the authors point out in the Introduction section, the authors' approach was to "separate the responding elements of the cell cycle from the regulatory elements," in order to sharpen their hypothesis regarding the role of these candidate cell cycle regulators. When reading this article, we would like you to imagine as if you were in the authors's situation (i.e. as if you don't have contemporary knowledge about cell cycle regulation) and think about what you can do or wish to do under such circumstances to understand cell cycle regulation, and compare your thoughts with the actual results and interpretations in the paper. On November 5th, we would like to discuss the paper in such style.

We try not to be too technical, but a basic textbook understanding of the cell cycle is desirable. Also, some basic knowledge about MPF and CSF as well as the Xenopus oocyte and early embryogenesis may aid in understanding the article. These information can be found here:

in English:
in Japanese: