Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Growing without a size checkpoint. | J. Biol. Journal of Biology BioMed Central Research news Growing without a size checkpoint Jonathan B Weitzman Published 24 April 2003 Journal of Biology 2002 2 3 The electronic version of this article is the complete one and can be found online at http content 2 1 3 2003 BioMed Central Ltd Mammalian cells unlike yeast seem to maintain a constant distribution of cell sizes without a cell-size checkpoint. Some scientific concepts are so taken for granted that they are no longer challenged despite a lack of experimental data to support them. Researchers who bravely challenge such widely accepted views often encounter resistance from others in the field. In this issue of the Journal of Biology 1 Ian Conlon and Martin Raff describe a series of experiments that questions a basic assumption about the way that mammalian cell size is maintained during proliferation and they demolish widely accepted doctrine see The bottom line box for a summary of their work . Most proliferating cells in culture maintain a constant distribution of sizes and a constant average size presumably by coordinating cell growth with progression through the cell division cycle. But it is far from clear how this coordination is orchestrated at the molecular level. Raff was perplexed that such a fundamental issue has attracted relatively little attention over the last couple of decades the impressive advances in understanding the mechanisms of cellcycle progression have vastly overshadowed any insights gained into how cells coordinate their growth with their size. It s quite inexplicable says Raff why this question has been so neglected. Yeast cell biologist Doug Kellogg University of California Santa Cruz USA shares Raff s amazement. We really don t know very much about this fundamental issue says Kellogg. It s one of the last big unsolved problems in cell biology. The history from yeast Much of the current understanding of cell growth comes from experiments performed in yeast which showed
