The objectives of this project are to elucidate the common biological, immunological, biophysical characteristics of the various defective (adeno-associated viruses (AAV)) and nondefective (Rat virus, H-1, MVM, Haden, DNV, PPV Lu III and PLV) viruses belonging to the family Parvoviridae. To better understand their mode of replication and persistence in the latent state and investigate their role in various degenerative diseases.