f1 is a bacteriophage. It is packaged in its viral capsid as a single stranded DNA genome. The origin was included in many plasmids to enable isolation of single strand DNA after infection of the plasmid-containing E. coli with the closely related M13 bacteriophage. One usually sees a + or - after the f1 to indicate the orientation of the ori which determined which strand was packaged. Single strand DNA previously was used for sequencing and mutagenesis (yes, way way back in the Dark Ages of Mo Bio!)

Short answer, if you haven't purposely infected your cells with M13 bacteriophage, then the f1 ori is totally non-functional, inert, and harmless.

Dear Farnaz,

It sounds like you are having a shuttle vector. As mentioned by Craig, the F1 origin belongs to the bacteriophage. Similarly, the pBR322 belongs to bacteria and ARS CEN to yeast.

Your vector has multiple oris for replication in multiple host systems.

Abhishek

Thank you Craig and Abhishek