Ram sperm mitochondrial DNA

Circular DNA was isolated from mitochondrial fractions of ram spermatozoa by SDS treatment followed by convex sucrose gradient centrifugation. The DNA had a contour length of 5.0 micron. Its buoyant density was 1.6983 g cm-3, which was smaller than two nuclear DNA components with buoyant densities of 1.6999 and 1.7156 g cm-3, found in ram spermatozoa. The Tm of the mitochondrial DNA was 69.7 degrees C. The mole fraction G+C calculated from the buoyant density and melting temperature was 39.1% and 38.6%, respectively.