Ongoing studies now focus on the molecular mechanisms of cell to cell communication through this novel glycoprotein. Cell biological studies are also underway that employ such techniques as sophisticated video imaging and image analysis to describe a detailed picture of how this protein influences cell to cell interaction. Studies are carried out in intact embryos as well as in a variety of tissue culture systems that employ isolated embryonic cells of the eye. A second major research thrust is the molecular analysis of gene regulation at the level of individual gene sequences. All genes possess regions that code for a product such as an enzyme.
All genes also have specific stretches of DNA that regulate expression of that gene.
We are currently using the techniques of molecular genetics to manipulate promoter gene sequences in an effort to pinpoint regulatory regions. Specific promoter sequences of identified genes are recombined with reporter genes that can be used to assay whether or not the promoter is actually working. Then the new construct is introduced into cultured cells or newly-fertilized zebrafish eggs. As the cells grow or the embryo develops, we monitor expression of the reporter gene. The embryonic fish can be used to determine whether or not the promoter sequence or some modification of that sequence possesses the information necessary for expression of the gene at the right time and place.