What are adeno-associated viruses, (AAV)?
Adeno-associated viruses are non-pathogenic human viruses. They are members of the Parvovirus family and are icosahedrally symmetrical and un-enveloped. The Parvovirus genome is made up of linear, monopartite ssDNA.that are dependant on a helper virus, (usually adenovirus), to proliferate. The AAV single stranded DNA genome contains two genes, rep and cap, which code for the required replicating and capsid proteins. Adeno-assoceated viruses contain within their promotor sequence a control element called the rep binding site, (rbs). AAV produces initial rep proteins that bind to the rbs causing minimal expression of the other rep proteins neccessary for reproduction of this virus. The helper virus interferes with the binding of the proteins at the rep site, allowing for expression of the rep proteins. In the absence of a helper virus, AAVs integrate into a specific point in the host genome with a high frequency. Integration occurs through a recombination event. This ability to integrate
