Adeno-associated viruses (AAVs), members of the Dependovirus genus of the subfamily Parvovirinae, family Parvoviridae, have single-stranded DNA genomes that replicate via a double-stranded DNA intermediate which serves as the transcription template. They exhibit a highly compact, overlapping genetic organization which is surprisingly variable amongst various members within the group. Additionally, recent work has shown them to be excellent models for understanding potential interactions between alternative splicing and alternative polyadenylation, the export of unspliced RNAs, and transactivating proteins that influence RNA processing co-transcriptionally via interaction with the transcription template.