replicon

Replicon is a unit of genetic material that is replicated as a single entity from a defined origin of replication. In bacteria and many organelles, a replicon corresponds to a self-contained DNA molecule such as a chromosome or a plasmid, each with its own origin and regulatory sequences that control initiation and copy number. In eukaryotes, replication proceeds from many origins along each chromosome; a replicon can be conceived as the DNA segment between adjacent origins or as the region governed by a single origin during a replication cycle.

Replication initiation involves initiator proteins and licensing factors. In bacteria, DnaA binds to oriC to start replication; in eukaryotes, the origin recognition complex (ORC) with Cdc6 and other factors licenses origins in G1 and activates them in S phase. Copy number and stability are influenced by origin efficiency, replication timing, and, for plasmids and organelles, copy-number control mechanisms.

Replicons are central to understanding genome organization and replication dynamics. Plasmid replicons are widely used in genetic engineering to maintain cloned genes and control dosage. In research, the replicon concept supports mapping origins of replication and studying replication timing and genome duplication.

The term replicon is also used as the name of Replicon Inc., a software company that provides time tracking and expense management solutions.