title: Physical analysis of a (dG + dC)-rich fraction of DNA obtained from the ovine genome.
abstract: Using the organomercuric compound 3,6-bis(acetatomercurimethyl)dioxane in conjunction with Cs2SO4 density gradient equilibrium centrifugation a (dG + dC)-rich DNA fraction constituting 10% of the ovine genome was separated from the remainder. Further fractionation allowed four distinct classes of DNA to be identified with buoyant densities in neutral CsCl of 1.714, 1.717, 1.725 and 1.716 g/cm3. Computerized curve resolving of the data indicated the presence of several additional DNA classes. Data obtained using restriction endonuclease digestion indicated that the 1.714 g/cm3 satellite consists principally of an 820-base pair (bp) tandemly repeating unit. The 820-bp DNA is also present in the 1.717 g/cm3 satellites but as a minor component. The principal components of the 1.717 and 1.725 g/cm3 fractions are 125-, 176- and 235-bp fragments. In addition, these fractions contain 705-bp tandemly repeated material. Two or possibly three species of 22-bp tandem repeats were found only in the 1.725 g/cm3 DNA.
mesh_terms: D000818:Animals; D001482:Base Composition; D004247:DNA; D004262:DNA Restriction Enzymes; D004276:DNA, Satellite; D003841:Deoxycytidine / Q000032:analysis*; D003849:Deoxyguanosine / Q000032:analysis*; D005796:Genes; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation; D012756:Sheep
chemical_list: D004276:DNA, Satellite; D003841:Deoxycytidine; D004247:DNA; D004262:DNA Restriction Enzymes; D003849:Deoxyguanosine