Figure 4.

A proposed role of the mitochondrial R-loop in strand-asynchronous replication. (A) According to Transcript-dependent Replication, mature transcripts hybridize to the lagging strand prior to second strand DNA synthesis (27). Because this mechanism of DNA replication starts in the Control Region (with the synthesis of a primer from LSP and transition to DNA synthesis at Ori-H, the first transcript required is a LC-RNA. LC-RNA dependent initiation of mtDNA replication is also compatible with the strand-displacement model, as illustrated.