This project will examine how different proteins which are synthesized by vertebrate photoreceptors are packaged and conveyed to their sites of secretion. It is known that each of these proteins is handled in a different manner, but it is not known how this complex process is regulated. The problem addressed, protein trafficking, is a very general one in cellular neurobiology and photoreceptors are the simplest structures in which the problem can be studied. Thus, the project will lead to a better understanding of the normal and pathological biology of nerve cells.