Polysphondylium pallidum is a cellular slime mold that forms distinctive spatial patterns during its like cycle. One of these patterns, the radial arrangement of spore-bearing arms about a central stalk, arises from a spheroidal mass of cells at the base of the developing organism. The emergence of the radial patterning from a spheroidal one is a true symmetry breaking event which Dr. Cox proposes to study in cellular and molecular detail by examining the structure and function of the genes involved. The genes coding for patterning elements will be studied by conventional cloning techniques and used to guess at possible functions; to study the timing and regulation of their transcripts; and to use them in antisense constructs and gene disruption experiments to ask whether or not the gene products are essential for development and morphogenesis. The long range goal of this research is a complete cellular understanding of morphogenesis in this simple system, with a view to relating the various contributions made by cell-cell signaling and physical interaction, the roles played by diffusible chemical signals, and the possible contribution to the process of forces such as cell movement, surface tension, and tissue deformation.
