Programming the Drosophila embryo 2: from genotype to phenotype.

Although development is a single hierarchical process, scientists tend to study only one level at a time: molecular, cellular, or organismal. The data and theory are available to integrate molecular, cellular, and organismal levels into a series of maps for development of the Drosophila embryo. These maps link the transcriptional cascade with mitotic and phenotypic fate maps to trace hierarchical mechanisms of development from the genotype in the egg to the phenotype in the larva.