Replicon (genetics)

Replicon (genetics)

A replicon is a DNA molecule or RNA molecule, or a region of DNA or RNA, that replicates from a single origin of replication.

Definition

The term replicon was first used in genetics to describe the portion of the genome that is replicated from a single origin of replication. It is now used to describe viral genomes, transposons, and other gene segments that manage their own replication, regardless of whether that replication is tied to the host's chromosome replication cycle.

Replicon Model

The replicon model was proposed by François Jacob, Sydney Brenner, and Matthew Meselson in 1963. This model suggests that the initiation of DNA replication depends on a certain sequence of DNA, the origin of replication, and a group of proteins, the initiators. The initiators bind to the origin of replication and unwind the DNA helix. This allows other proteins to bind and start the replication process.

Replicon in Viruses

In viruses, the replicon includes the genome or part of the genome. Viral replicons can be used in genetic engineering to create a plasmid or vector that expresses a particular gene in cells that the vector is introduced into. This is a common method used in molecular biology to make copies of a particular gene.

Replicon in Bacteria

In bacteria, the replicon is typically a circular DNA molecule that is replicated independently of the chromosome. Plasmids, transposons, and some bacteriophages have their own replicons.

See Also

• DNA replication
• Origin of replication
• Plasmid
• Transposon
• Bacteriophage

References

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