Gene expression in the developing rat mandible: a gene array study

To analyse the molecular events that occur in the developing mandible, gene arrays containing probes for 1176 known genes were used. Total RNA was extracted from the mandibles of 1- and 6-day-old rats. Radiolabeled probes were then synthesised and used to probe the DNA arrays. Of the 1176 genes examined, 306 were detectable, and the latter were analyzed by bioinformatics algorithms. K-means clustering grouped 72 genes into Up, 56 genes into Down and 178 genes into NO change. A large number of genes related to cell receptors (by ligands) were grouped into the Down cluster. Gene array technology appears to be a useful tool for studying the complex process of mandibular development.