tailieunhanh - Báo cáo khoa học: Gene expression waves Cell cycle independent collective dynamics in cultured cells

The ergodic hypothesis, which assumes the independence of each cell of the ensemble from all the others, is a necessary prerequisite to attach single cell based explanations to the grand averages taken from population data. This was the prevailing view about the interpretation of cellular biology experi-ments that typically are performed on colonies of billions of cells. | ễFEBS Journal Gene expression waves Cell cycle independent collective dynamics in cultured cells Masa Tsuchyia1 Sum T. Wong2 Zhen X. Yeo3 Alfredo Colosimo4 Maria C. Palumbo4 Lorenzo Farina5 Marco Crescenzi6 Alessia Mazzola6 Rodolfo Negri7 Michele M. Bianchi7 Kumar Selvarajoo1 Masaru Tomita1 and Alessandro Giuliani6 1 Institute for Advanced Biosciences Keio University Yamagata Japan 2 Bioinformatics Institute Singapore 3 Genome Institute of Singapore Singapore 4 Physiology and Pharmacology Department University of Rome La Sapienza Italy 5 Department of Computer and Systems Science University of Rome La Sapienza Italy 6 Istituto Superiore di Sanita Environment and Health Department Rome Italy 7 Department of Celland DevelopmentalBiology University of Rome La Sapienza Italy Keywords cell-cellcommunication metabolic cycle microarray ribogenesis cycle systems biology Correspondence A. Giuliani Istituto Superiore di Sanita Environment and Health Department Viale Regina Elena 299 00161 Rome Italy Fax 39 0649 902999 Tel 39 0649 902579 E-mail Received 1 March 2007 revised 28 March 2007 accepted 3 April 2007 The ergodic hypothesis which assumes the independence of each cell of the ensemble from all the others is a necessary prerequisite to attach single cell based explanations to the grand averages taken from population data. This was the prevailing view about the interpretation of cellular biology experiments that typically are performed on colonies of billions of cells. By analysing gene expression data of different cells going from yeast to mammalian cell cultures we demonstrate that cell cultures display a sort of ecology-in-a-plate giving rise to a rich dynamics of gene expression that are independent from reproductive cycles hence contradicting simple ergodic assumptions The aspecific character of the observed coordinated gene expression activity inhibits any simple mechanistic hypothesis and highlights the need to consider population effects