title: [Site of nuclear DNA replication in embryonic cells of the sea urchin Strongylocentrotus intermedius].
abstract: In the sea urchin embryonic cells, all newly synthesized nuclear DNA (n-DNA) pulse-labeled by 3H-thymidine was found within DNA-membrane complex (DNA-mc) isolated by centrifugation of lysates of nuclei after their treatment with Sarkosyl, Brij-35, or sodium dodecylsulfate through neutral sucrose (10--30%) gradients. This attachment has been shown not to be an artifact due to the unspecific effect of the detergents or the destabilization of the secondary structure of n-DNA because the association of the exogenous 14C-DNA with nuclear membrane and chromatin did not occur during the isolation of the DNA-mc. n-DNA was not replaced from DNA-mc when the latter was isolated in the excess of unlabeled denatured DNA. n-DNA associated with DNA-mc behaved as a precursor of chromosomal DNA. It is suggested that in sea urchin embryonic cells the synthesis of nuclear DNA is carried out by the replicative complex attached to the nuclear membrane.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication; D004625:Embryo, Nonmammalian; D005260:Female; D007700:Kinetics; D009685:Nuclear Envelope / Q000378:metabolism; D009691:Nucleic Acid Denaturation; D012617:Sea Urchins / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism
chemical_list: D002843:Chromatin; D004247:DNA; D013936:Thymidine
vernacular_title: Issledovanie mesta replikatsii iadernoi DNK e embrinov morskogo ezha Strongylocentrotus intermedius.