The encapsidation of polyomavirus is not defined by a sequence-specific encapsidation signal.

Mouse polyomavirus (MPyV) is considered a potential tool for the application of gene therapy; however, the current knowledge of the encapsulation of DNA into virions is vague. We used a series of assays based on the encapsidation of a reporter vector into MPyV pseudovirions to identify putative cis-acting elements that are involved in DNA encapsidation. None of the sequences that were derived from MPyV have been shown to solely enhance the encapsidation of a reporter vector in the assay.

The Cre/loxP recombination system for production of infectious mouse polyomavirus.

Murine polyomavirus mutants are frequently produced for experimental as well as therapy purposes. Commonly used methods for preparation of mutant viral genomes from recombinant vectors are laborious and give variable yields and quality. We describe an efficient and reproducible Cre/loxP-mediated recombination system that generates polyomavirus genomes from recombinant plasmid in vivo.