Gene expression profiling in time and space within a population of cells can be used to generate a molecular movie of development. Birnbaum et al. describe an analytical approach to provide such a map in the context of the Arabidopsis root tip. Global expression patterns within the organ were mined to infer novel aspects of development, which included the discovery of organizing signals that could play important roles in cell fate and differentiation in Arabidopsis.
K. Birnbaum, D. E. Shasha, J. Y. Wang, J. W. Jung, G. M. Lambert, D. W. Galbraith, P. N. Benfey, A gene expression map of the Arabidopsis root. Science 302, 1956-1960 (2003). [Abstract] [Full Text]