Experimental approaches to determine gene expression profiles of normal and diabetes-exposed embryos. Panels A and B depict the two independent microarray experiments. Panels C and D depict expression profiles where each colored vertical line represents the expression signal for one gene and row represent individual embryos (Exp. I) or samples (Exp. II). Red represents increased expression, blue reflects decreased expression, and intermediate colors represent minor changes (the color range was chosen along an arbitrary scale). Using a hierarchical clustering algorithm (with euclidean distance metric and centroid linkage rule, as implemented in GeneSpring), these graphic representations shows that expression profiles for embryos exposed to maternal diabetes differ considerably from control unexposed embryo profiles.