The circularity of mitochondrial DNA.

Abstract

Evidence has been presented that mitochondrial DNA of L cells exists in circular form either when extruded from osmotically lysed organelles or extracted by phenol. In contrast, nuclear DNA is linear. Mitochondrial DNA appears to be membrane-bound at one or more sites. The molecular weight of mitochondrial DNA was estimated by electron microscopic and by chemical methods. Two to 6 ring molecules of molecular weight 10 x 106 may be present in single mitochondrion. Some of the implications of these findings were discussed.