Retroviral vector, a replication system for said vector and avian or mammalian cells transfected with said vector

摘要

A retroviral vector comprising a retrovirus with infectivity for birds and/or mammals in which at least part of the genomic RNA sequences carrying information for the production of viral proteins required in trans for retroviral replication have been replaced by one or more sequences carrying information to be introduced in a target cell chromosome, characterized in that the primer binding site (PBS) has been modified to a sequence that does not allow strong base pairing with the 3' end or other priming sequence in any naturally occurring tRNA.