Flower development remains one of the most interesting and complex processes unique to plants, and yet little is known about the molecular mechanisms involved. Dr. Yanofsky has cloned one of the genes, Agamous (AG), that plays a key role in determining the correct pattern of floral organs in Arabidopsis thaliana. Mutations in the AG gene result in a "double flower" phenotype. Similar phenotypes have been described in other plants for as much as two thousand years, making this the oldest recognized flower abnormality. Dr. Yanofsky's goal over the next three to five years is to begin to dissect the complex regulatory network that allows the expression of the AG gene to be controlled such that expression occurs in a precise spacial and temporal manner. This will be achieved through a detailed characterization of the cis acting elements involved in regulation the expression of AG, and by identifying the sequences within the AG promoter to which trans acting regulatory factors bind. In addition, since the data suggest that the Agamous protein is a sequence specific DNA binding protein that regulates genes involved in stamen and carpel formation, he will directly test the ability of AGamous to recognize specific DNA sequences. In addition, by manipulating the expression of Agamous in transgenic plants, he will directly test predictions of a model for flower development that has thus far been based entirely on genetic data.