The object of this project is to study diseases of the exocrine and endocrine portions of the pancreas with emphasis on diabetes mellitus. At the present time, an animal model for viral induced diabetes is being investigated. Special attention is being given to: 1) genetic differences in susceptibility to viral induced diabetes; 2) purification, cultivation and characterization of beta cells from both animals and man; and 3) effect of various factors, including viruses, on the functional capacity of beta cells.