title: Effect of triiodothyronine (T3) on ribonucleic acid polymerase activity in developing tadpole hindlimb.
abstract: Optimum conditions were studied for the determination of RNA polymerase activity in nuclei isolated from Rana catesbeiana tadpole hindlimbs. Tadpole nuclei were tested at 15 degrees C in the presence of spermidine (1.5 mM) bovine serum albumin (1.0%) and a high concentration of nucleoside triphosphates (1.0 mM). Tadpole nuclei exhibited a 60-70% higher total RNA polymerase activity with maximum activity of RNA polymerase I at 4 hr and RNA polymerase II at 8 hr after triiodothyronine injection. The results support a nuclear mechanism for the differentiation of tadpole hindlimbs induced by triiodothyronine.
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002467:Cell Nucleus / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D006614:Hindlimb; D007814:Larva / Q000201:enzymology; D012318:RNA Polymerase I / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D011892:Rana catesbeiana / Q000196:embryology*; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D014284:Triiodothyronine; D012319:RNA Polymerase II; D012318:RNA Polymerase I