title: Presence of two deoxyribonucleic acid polymerases in bull spermatozoa.
abstract: A DNA polymerase-endogenous template complex was isolated from nuclear heads of bull spermatozoa. The buoyant density of the complex was 1.15 g/cm 3. The sedimentation coefficient of the nuclear DNA polymerase isolated from the complex was higher at low ionic strength, but approached 3.4S when centrifuged in a medium containing 2M-KCl. Activated exogenous DNA increased polymerase activity. Only very low activities were detected with synthetic templates such as poly(A).(dT)12-18 and poly(dT).poly(A). The nuclear reaction was stimulated by 150mM-KCl and was slightly inhibited by N-ethylmaleimide; it was resistant to actinomycin D, netropsin and ethidium bromide. Another DNA polymerase, highly sensitive to ethidium bromide, was extracted from the mitochondira-rich middle-piece fraction. Its sedimentation coefficient was close to 9S, but fell to approx. 4S in high-ionic-strength medium.
mesh_terms: D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000201:enzymology; D002499:Centrifugation, Density Gradient; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D008928:Mitochondria / Q000201:enzymology; D013077:Sperm Head / Q000201:enzymology* / Q000648:ultrastructure; D013094:Spermatozoa / Q000201:enzymology*; D013698:Templates, Genetic
chemical_list: D004259:DNA-Directed DNA Polymerase