tailieunhanh - Báo cáo sinh học: "Differences in the way a mammalian cell and yeast cells coordinate cell growth and cell-cycle progression"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Differences in the way a mammalian cell and yeast cells coordinate cell growth and cell-cycle progression. | J. Biol. Journal of Biology BioMed Central Research article Open Access Differences in the way a mammalian cell and yeast cells coordinate cell growth and cell-cycle progression Ian Conlon and Martin Raff Address MRC Laboratory for Molecular Cell Biology and Cell Biology Unit University College London London WC1E 6BT UK. Correspondence Martin Raff. E-mail Published 24 April 2003 Received 2 December 2002 Revised 6 March 2003 Journal of Biology 2003 2 7 J I gy Accepted 18 March 2003 The electronic version of this article is the complete one and can be found online at http content 2 1 7 2003 Conlon and Raff licensee BioMed Central Ltd. This is an Open Access article verbatim copying and redistribution of this article are permitted in all media for any purpose provided this notice is preserved along with the article s original URL. Abstract Background It is widely believed that cell-size checkpoints help to coordinate cell growth and cell-cycle progression so that proliferating eukaryotic cells maintain their size. There is strong evidence for such size checkpoints in yeasts which maintain a constant cell-size distribution as they proliferate even though large yeast cells grow faster than small yeast cells. Moreover when yeast cells are shifted to better or worse nutrient conditions they alter their size threshold within one cell cycle. Populations of mammalian cells can also maintain a constant size distribution as they proliferate but it is not known whether this depends on cell-size checkpoints. Results We show that proliferating rat Schwann cells do not require a cell-size checkpoint to maintain a constant cell-size distribution as unlike yeasts large and small Schwann cells grow at the same rate which depends on the concentration of extracellular growth factors. In addition when shifted from serum-free to serum-containing medium Schwann cells take many divisions to increase their size to that appropriate to the new condition suggesting .