The Arabidopsis thaliana floral homeotic gene, AGAMOUS (AG), and six additional genes, AGL1-AGL6, have been isolated. Their sequences share striking similarity with the DNA binding domain of transcription factors from humans (SRF) and yeast (MCM1), which regulate the expression of the human proto-oncogene c-fos and yeast mating type specific genes, respectively. AG and five of the AGLs are expressed preferentially in flowers, while AGL3 is expressed both in flowers and in vegetative tissues. Dr. Ma proposes to dissect the functional domains of AG using mutational analysis, promoter fusions, and domain switching. Furthermore, he proposes to characterize the structure and expression of the AGL3 gene, which has a unique expression pattern among these seven genes, and may play a more fundamental role in both reproductive and vegetative tissues. Finally, because the yeast MCM1 gene has the same type of DNA binding domain, and because powerful genetic and molecular tools are available in yeast, he proposes to study some functional aspects of the AG protein in yeast. The combination of these methods in both plant and yeast will lead to a better understanding of the function of these plant genes.
