Mitochondria use different origin sequences to initiate replication of each DNA strand

Replication of the H strand is initiated in a D loop.

Replication of the L strand is initiated when its origin is exposed by the movement of the first replication fork.

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Deletion of the ter sites does not, however, prevent normal replication cycles from occurring, although it does affect segregation of the daughter chromosomes.

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The two replication forks meet and halt in a region approximately halfway around the chromosome from the origin.

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 In E. coli, two clusters of five ter sites each, including terk, -I, -E, -D, and -A on one side and terC, -B, -F, -G, and -H on the other, are located -100 kb on either side of this termination region.

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Each set of ter sites allows a replication fork into the termination region, but does not allow it out the other side.For example, replication fork 1 can pass through terC and terB into the region, but it cannot continue past terE, -D, and -A. This arrangement creates a "replication fork trap."

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 mtDNA replication and segregation to daughter mitochondria is stochastic.

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Mitochondrial segregation to daughter cells is also stochastic.