Rolling Circle Replication, Sigma Mode Replication, Greek Letter Sigma, Circular DNA, Replication of a Circle Tail, Progeny DNA, Genomes

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	Rolling Circle Replication - This type of replication is seen in some animal viruses such as lambda (A) viruses. The replicating fork resembles that in E coli DNA replication, with continuous synthesis on the leading strand and discontinuous synthesis on the lagging strands. One can actually imagine the replicating DNA as a roll of toilet paper unrolling as it speeds across the floor.
In the rolling circle mode of replication, a nick is made in one of the strands of the circular DNA, resulting in the replication of a circle and a tail. The unrolled part represents the growing double-stranded progeny DNA. The progeny DNA is several genomes long before it is packaged. These multiple-length DNAs are called as concatemers. This mode of replication is sometimes also called sigma mode replication because the intermediates resemble the lower case Greek letter sigma (σ).