title: Base excision DNA repair in the embryonic development of the sea urchin, Strongylocentrotus intermedius.
abstract: In actively proliferating cells, such as the cells of the developing embryo, DNA repair is crucial for preventing the accumulation of mutations and synchronizing cell division. Sea urchin embryo growth was analyzed and extracts were prepared. The relative activity of DNA polymerase, apurinic/apyrimidinic (AP) endonuclease, uracil-DNA glycosylase, 8-oxoguanine-DNA glycosylase, and other glycosylases was analyzed using specific oligonucleotide substrates of these enzymes; the reaction products were resolved by denaturing 20% polyacrylamide gel electrophoresis. We have characterized the profile of several key base excision repair activities in the developing embryos (2 blastomers to mid-pluteus) of the grey sea urchin, Strongylocentrotus intermedius. The uracil-DNA glycosylase specific activity sharply increased after blastula hatching, whereas the specific activity of 8-oxoguanine-DNA glycosylase steadily decreased over the course of the development. The AP-endonuclease activity gradually increased but dropped at the last sampled stage (mid-pluteus 2). The DNA polymerase activity was high at the first cleavage division and then quickly decreased, showing a transient peak at blastula hatching. It seems that the developing sea urchin embryo encounters different DNA-damaging factors early in development within the protective envelope and later as a free-floating larva, with hatching necessitating adaptation to the shift in genotoxic stress conditions. No correlation was observed between the dynamics of the enzyme activities and published gene expression data from developing congeneric species, S. purpuratus. The results suggest that base excision repair enzymes may be regulated in the sea urchin embryos at the level of covalent modification or protein stability.
authors.affiliation: Institute of Chemical Biology and Fundamental Medicine SB RAS, 8 Lavrentieva Ave., Novosibirsk 630090, Russia. dzharkov@niboch.nsc.ru nevinsky@niboch.nsc.ru and Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russia.
authors.forename: Natalya A
authors.initials: NA
authors.lastname: Torgasheva
authors.affiliation: G. B. Elyakov Pacific Institute of Bioorganic Chemistry FEB RAS, 159 100 let Vladivostoku Ave., Vladivostok 690022, Russia.
authors.forename: Natalya I
authors.initials: NI
authors.lastname: Menzorova
authors.affiliation: G. B. Elyakov Pacific Institute of Bioorganic Chemistry FEB RAS, 159 100 let Vladivostoku Ave., Vladivostok 690022, Russia.
authors.forename: Yurii T
authors.initials: YT
authors.lastname: Sibirtsev
authors.affiliation: G. B. Elyakov Pacific Institute of Bioorganic Chemistry FEB RAS, 159 100 let Vladivostoku Ave., Vladivostok 690022, Russia.
authors.forename: Valery A
authors.initials: VA
authors.lastname: Rasskazov
authors.affiliation: Institute of Chemical Biology and Fundamental Medicine SB RAS, 8 Lavrentieva Ave., Novosibirsk 630090, Russia. dzharkov@niboch.nsc.ru nevinsky@niboch.nsc.ru and Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russia.
authors.forename: Dmitry O
authors.initials: DO
authors.lastname: Zharkov
authors.affiliation: Institute of Chemical Biology and Fundamental Medicine SB RAS, 8 Lavrentieva Ave., Novosibirsk 630090, Russia. dzharkov@niboch.nsc.ru nevinsky@niboch.nsc.ru and Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russia.
authors.forename: Georgy A
authors.initials: GA
authors.lastname: Nevinsky
mesh_terms: D000818:Animals; D004260:DNA Repair; D004625:Embryo, Nonmammalian; D047108:Embryonic Development / Q000235:genetics*; D004789:Enzyme Activation; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D016678:Genome; D023281:Genomics / Q000379:methods; D016366:Open Reading Frames; D047269:Strongylocentrotus / Q000196:embryology* / Q000235:genetics*; D051981:Uracil-DNA Glycosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D051981:Uracil-DNA Glycosidase