title: A study of interfering herpes simplex virus DNA preparations containing defective genomes of either class I or II and the identification of minimal requirements for interference.
abstract: Progeny DNA of herpes simplex virus type 1 (HSV-1) strain ANG from infections involving defective interfering virus particles (DI DNA) has been described to be of low infectivity in transfection assays due to the presence of viral genomes that interfere with plaque formation by infectious standard genomes. In this study it is shown that this observation applies both for DI DNA containing repetitive defective DNA of the class I type and for DI DNA containing class II-type defective DNA. Restriction endonucleases with recognition sites only in one class of repetitive defective DNA could be used to reduce selectively the interfering activity of DI DNA preparations containing the respective defective DNA in abundance. The results obtained directly implicate repetitive defective DNA as an interfering agent. Restriction endonucleases that create monomeric DNA fragments from class II HSV-1 ANG defective DNA did not abolish the interfering activity of DI DNA containing this type of defective DNA in high abundance, indicating that it is not simply the repetitive nature of defective DNA that is required for interference. Certain DNA fragments shorter than the repeat unit of repetitive defective DNA were still capable of causing interference even in the absence of cohesive single-stranded ends. The common location of cis recognition signals responsible for progeny DNA maturation and initiation of DNA replication on one DNA fragment, however, appeared to be a minimal requirement for interference by fragmented defective DNA.
mesh_terms: D000818:Animals; D001483:Base Sequence; D004262:DNA Restriction Enzymes / Q000494:pharmacology; D004279:DNA, Viral / Q000032:analysis / Q000502:physiology*; D003673:Defective Viruses / Q000502:physiology*; D018139:Simplexvirus / Q000235:genetics*; D014162:Transfection; D014762:Viral Interference
chemical_list: D004279:DNA, Viral; D004262:DNA Restriction Enzymes