The ability to detect spatial and temporal patterns in gene expression and to test gene function using targeted disruption or misexpression of specific genes has enhanced understanding of the roles that specific genes play during the development of organs and organ systems.  Events, such as specification of the organ primordia, inductive signaling, outgrowth, and patterning, are routinely investigated at the level of molecular genetic mechanisms.  One theme that has emerged from these studies is the conserved role of growth factors, signaling molecules, and signaling pathways across vastly different animal species and organs.  This universality of molecular mechanisms is giving rise to a template for organ morphogenesis.  The DBGT Branch Organogenesis Program supports research to examine: 
· Development of the limb, including cartilage and bone primordia;
· Somitogenesis, including development of skeletal and muscular elements; and
· Establishment of the gut, heart, lung, pituitary, kidney, and other organ primordia.

Limb Development, Chondrogenesis, and Myogenesis. This program focuses on the development of connective and supportive tissues, with emphasis on embryonic maturation of the limb. Of particular program interest are molecular, biochemical and morphological studies addressing limb outgrowth and pattern formation, and the underlying mechanisms associated with chondrogenesis, somite formation, the regulation of myogenesis, and the formation of neuromuscular junctions. Also of interest are studies identifying the mechanisms supporting regeneration.

Teratology.  This area assesses adverse genetic and environmental influences on development, and seeks to clarify mechanisms by which developmental aberrations are produced. Structural defects such as neural tube defects, normal and abnormal limb development, and associated anomalies are given special emphasis, though subtle long term effects on the CNS and other organs are also examined. The bioeffects of ultrasound, magnetic resonance imaging, and environmentally induced defects are also of special interest as well as tissue specific selective susceptibility to teratogenic insult.