Dr. John Fessler's research seeks to understand the molecular biology of how drosophila embryo cells collaborate to form a tissue. Basement membranes are fundamental to tissue construction. These thin nets of specialized, conserved extracellular proteins underlie epithelial cells and surround muscles and nerves. Fessler's lab has isolated, cloned and sequenced several of the component proteins, such as laminin and collagen, and is now studying mutant forms, the control of production and interactions during development. Three new proteins are of special interest: peroxidasin, papilin and a drosophila ADAMTS protease.