Replication of Mouse L-cell Mitochondrial DNA

Abstract

Mitochondrial DNA (mtDNA) of mouse L cells employs a very distinctive replication mechanism, termed asynchronous displacement replication, which was proposed several years ago on the basis of electron microscopic analyses of replicating molecules (Kasamatsu et al. 1971; Robberson et al. 1972; Kasamatsu and Vinograd 1973; reviewed by Kasamatsu et al. 1974 and Kasamatsu and Vinograd 1974). Subsequent pulse-chase labeling experiments in our laboratory have corroborated and refined this model. These studies have revealed a marked asynchrony in the synthesis of the two complementary strands of mtDNA, which are separable into a heavy (H) and a light (L) strand by equilibrium centrifugation in alkaline CsCl gradients.