Nuclear matrix-associated DNA fragments enhance autonomous replication of plasmids in chicken cells

Most cells of higher eukaryotes may maintain several rounds of replication of circular DNA. Efficiency of replication is usually low, and depends on the length of the circular DNA rather than on the sequence context. We have isolated and characterized several short DNA fragments that form structural sites of attachment to the nuclear matrix (nmDNA) in chicken cells, and tested whether they would enhance autonomous replication of DNA in chicken cells as compared to the vector DNA. Indeed, a several-fold increase in a short-term replication efficiency was detected using a semi-conservative replication and a DpnI-resistance assay. Most of the cloned matrix-associated fragments were recovered in the nuclear matrix fraction when introduced into cultured chicken cells as a circular DNA. The data obtained suggest that the observed enhancement in the replication efficiency of the circular DNA may be due to their recruitment to the nuclear matrix by the nmDNA.