title: Genome-wide analysis of gene expression profiles associated with cell cycle transitions in growing organs of Arabidopsis.
abstract: Organ growth results from the progression of component cells through subsequent phases of proliferation and expansion before reaching maturity. We combined kinematic analysis, flowcytometry, and microarray analysis to characterize cell cycle regulation during the growth process of leaves 1 and 2 of Arabidopsis (Arabidopsis thaliana). Kinematic analysis showed that the epidermis proliferates until day 12; thereafter, cells expand until day 19 when leaves reach maturity. Flowcytometry revealed that endoreduplication occurs from the time cell division rates decline until the end of cell expansion. Analysis of 10 time points with a 6k-cDNA microarray showed that transitions between the growth stages were closely reflected in the mRNA expression data. Subsequent genome-wide microarray analysis on the three main stages allowed us to categorize known cell cycle genes into three major classes: constitutively expressed, proliferative, and inhibitory. Comparison with published expression data obtained from root zones corresponding to similar developmental stages and from synchronized cell cultures supported this categorization and enabled us to identify a high confidence set of 131 proliferation genes. Most of those had an M phase-dependent expression pattern and, in addition to many known cell cycle-related genes, there were at least 90 that were unknown or previously not associated with proliferation.
authors.affiliation: Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology, Ghent University, B-9052 Ghent, Belgium.
authors.forename: Gerrit T S
authors.initials: GT
authors.lastname: Beemster
authors.forename: Lieven
authors.initials: L
authors.lastname: De Veylder
authors.forename: Steven
authors.initials: S
authors.lastname: Vercruysse
authors.forename: Gerrit
authors.initials: G
authors.lastname: West
authors.forename: Debbie
authors.initials: D
authors.lastname: Rombaut
authors.forename: Paul
authors.initials: P
authors.lastname: Van Hummelen
authors.forename: Arnaud
authors.initials: A
authors.lastname: Galichet
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Gruissem
authors.forename: Dirk
authors.initials: D
authors.lastname: Inzé
authors.forename: Marnik
authors.initials: M
authors.lastname: Vuylsteke
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics* / Q000254:growth & development; D002453:Cell Cycle / Q000235:genetics*; D049109:Cell Proliferation; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D018745:Genome, Plant; D018515:Plant Leaves / Q000378:metabolism