Multicopy plasmid with a structure related to the polyoma virus genome

T. Kusano, H. Uehara, H. Saito, K. Segawa, M. Oishi

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


In a subclone derived from mouse L(tk-) cells, we found a plasmid present in a high copy number (> 5000 copies per cell) that was stably maintained extrachromosomally without any cytopathic effect to the host cells. This plasmid, termed L factor, has two forms: 5.3 and 5.5 kilobase pairs. DNA sequencing and restriction enzyme mapping showed that, although the structure contains DNA sequences common to polyoma virus, plasmid sequences belonging to the regulatory region (the enhancer region) and other regions are quite different from those in polyoma. In cells bearing the plasmid, we detected a low level of material that cross-reacts with antibody to polyoma tumor antigens, suggesting that the plasmids replicate and are maintained in the cells by a mechanism different from that functioning during propagation following infection of papovaviruses.

Original languageEnglish
Pages (from-to)1789-1793
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number7
Publication statusPublished - 1987
Externally publishedYes

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Multicopy plasmid with a structure related to the polyoma virus genome'. Together they form a unique fingerprint.

Cite this