title: Activity of a DNA topoisomerase (nicking-closing enzyme) during sea urchin development and the cell cycle.
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D012617:Sea Urchins / Q000196:embryology* / Q000201:enzymology
chemical_list: D002843:Chromatin; D004264:DNA Topoisomerases, Type I