Nondefective spleen necrosis virus-derived vectors define the upper size limit for packaging reticuloendotheliosis viruses.
We constructed a nondefective retrovirus vector based on spleen necrosis virus (SNV), a replication-competent reticuloendotheliosis virus. We introduced different DNA sequences into this vector and studied the ability of the resulting viruses to replicate in chicken embryo fibroblasts. The replication efficiency of SNV-derived viruses decreased with increasing virus size. Viruses larger than 9.4 kilobases (kb) were rapidly overgrown by replication-competent deletion mutants. The size restriction for the efficient replication of nondefective SNV-derived viruses prevented the production of viruses larger than 10.0 kb. Analysis of the kinetics of virus particle release indicated that the size restriction occurred during virus encapsidation.
D002213:Capsid; D005822:Genetic Vectors; D009052:Leukemia Virus, Murine / Q000235:genetics*; D008970:Molecular Weight; D009024:Morphogenesis; D012367:RNA, Viral / Q000235:genetics; D013155:Spleen Focus-Forming Viruses / Q000235:genetics* / Q000254:growth & development; D014779:Virus Replication
D012367:RNA, Viral