Expression data from metanephric mesenchyme induced to convert into nephron epithelia

During kidney development segmented epithelia of the nephron derive from progenitor cells in the metanephric mesenchyme after induction by secreted molecules from the ureteric bud. We have identified three distinct inductive activities from a ureteric bud cell line. These include leukemia inhibitory factor (LIF), neutrophil gelatinase-associated lipocalin (NGAL) and an active fraction currently referred to as ANX. Each of these activities induces segmented nephron epithelia in isolated rat metanephric mesenchyme over a time period of 7 days. This study was designed to characterize the temporal sequence of gene expression in the course of the conversion process induced by each of the distinct inducers. Keywords: time course Metanephric mesenchymes were microdissected from rat E13.5 embryos. Mesenchymes were cultured on transwells in the presence of either LIF, NGAL or the ANX fraction and RNA was harvested after 1, 2, 3, 4, 5, and 7 days for RNA extraction. Freshly dissected mesenchymes and mesenchymes cultured in the absence of inducers for 1 and 2 days, respectively, served as controls. Each condition was analyzed in duplicate (biological replicates). Biotinylated cRNA was prepared and hybridized to Affymetrix Rat Genome 230 2.0 Microarrays. Expression values were obtained by robust multichip analysis.