Mitochondrial DNA from Representative Species of Reptilia and Cnidaria

Abstract

<p>Radioactive thymidine was used to label DNA in turtle fibroblasts grown in tissue culture. The circular mDNA was separated from the linear nDNA on EB-CsCl gradients. The buoyant densities of both DNAs were determined on CsCl gradients by comparison with Micrococcus lysodecticus DNA. The buoyant densities of the two DNAs were found to be less than 2 mg cmˉ³ apart and were 1.704 gm cmˉ³ ± 2 mg cmˉ³.</p> <p>Mitochondrial DNA was isolated from turtle livers and subjected to electron microscopy. Electron micrographs showed that turtle mDNA was of a similar size to mDNA isolated from rat and hamster liver.</p> <p>Hydra littoralis were cultured and the mitochondrial fraction of a homogenate of hydra polyps identified. The DNA from this fraction was extracted and electron microscopy indicated that the molecules may have been circular in vivo and have a length slightly longer than 5 μm.</p>