Kinetoplast DNA minicircles: high-copy-number mitochondrial plasmids.

The kinetoplast DNA of trypanosomes is a highly unusual network of catenated DNA circles of two kinds: maxicircles, the equivalent of conventional mitochondrial DNA, and minicircles, high-copy-number mitochondrial plasmids with no known function. Kinetoplast minicircles share many features with bacterial plasmids and represent a novel model system for the study of the mechanisms and regulation of DNA replication in eukaryotic organisms.