title: Effects of seawater acidification on cell cycle control mechanisms in Strongylocentrotus purpuratus embryos.
abstract: Previous studies have shown fertilization and development of marine species can be significantly inhibited when the pH of sea water is artificially lowered. Little mechanistic understanding of these effects exists to date, but previous work has linked developmental inhibition to reduced cleavage rates in embryos. To explore this further, we tested whether common cell cycle checkpoints were involved using three cellular biomarkers of cell cycle progression: (1) the onset of DNA synthesis, (2) production of a mitotic regulator, cyclin B, and (3) formation of the mitotic spindle. We grew embryos of the purple sea urchin, Strongylocentrotus purpuratus, in seawater artifically buffered to a pH of ∼7.0, 7.5, and 8.0 by CO(2) infusion. Our results suggest the reduced rates of mitotic cleavage are likely unrelated to common cell cycle checkpoints. We found no significant differences in the three biomarkers assessed between pH treatments, indicating the embryos progress through the G(1)/S, G(2)/M and metaphase/anaphase transitions at relatively similar rates. These data suggest low pH environments may not impact developmental programs directly, but may act through secondary mechanisms such as cellular energetics.
authors.affiliation: Department of Biological Sciences and The Environment and Sustainability Program, University of South Carolina, Columbia, South Carolina, United States of America. places@mailbox.sc.edu
authors.forename: Sean P
authors.initials: SP
authors.lastname: Place
authors.forename: Bryan W
authors.initials: BW
authors.lastname: Smith
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002453:Cell Cycle; D018385:Centrosome / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006863:Hydrogen-Ion Concentration; D008938:Mitosis; D008954:Models, Biological; D012623:Seawater; D008941:Spindle Apparatus; D047270:Strongylocentrotus purpuratus / Q000196:embryology*; D013997:Time Factors; D014404:Tubulin / Q000737:chemistry
chemical_list: D015415:Biomarkers; D019926:Cyclin B; D014404:Tubulin; D001973:Bromodeoxyuridine