Arabidopsis thaliana Ler developmental series

Leaf development has been monitored chiefly by following anatomical markers. Analysis of transcriptome dynamics during leaf maturation revealed multiple expression patterns that rise or fall with age or that display age specific peaks. These were used to formulate a digital differentiation index (DDI), based on a set of selected markers with informative expression during leaf ontogeny. The leaf-based DDI reliably predicted the developmental state of leaf samples from diverse sources and was independent of mitotic cell division transcripts or propensity of the specific cell type. To calibrate and test the DDI a series of Arabidopsis shoot development was used (Efroni et al, 2008) Four samples from different stages of shoot and leaf development taken from plants grown at short days (10 hours light at 20C), starting from 5 days after sowing (DAS) apices to 35 DAS fully expanded leaves. RNA was hybridized to affymatrix ATH1 arrays and done in duplicates.