Figure 2: Developmental sites of action in flies, worms, and mice. Selected key organ systems and broad patterning functions for nuclear receptors in development are shown. Color scheme at right identifies specific NRs by overall class. Some functions are indicated at the temporal stage at which they are observed, but may function earlier. Genes assigned to the “pattern” class may have roles in specifying embryonic region (e.g. tll), major embryonic events such as gastrulation (e.g. E78), or early cell divisions (e.g. LRH-1, TR2). Illustrations are not to scale. Artwork is by S. Bodofsky.