LE3 .A278 2016

2016

Gibson, Glenys

Acadia University

Bachelor of Science

Honours

Biology

Biology

Adults of some species have the capacity to regenerate lost body parts, a process mediated by the molecular processes of gene regulation. Model organisms for regeneration include salamanders, hydra, and planarian flatworms. The spionid polychaete Pygospio elegans, a small marine invertebrate common in estuaries and mud flats in the North Atlantic, has the capacity to regenerate lost structures with fidelity to its original body plan in as little as eight days. I investigated the potential effects of a common environmental contaminant on regeneration, bisphenol-A (BPA), a compound that is known to disrupt embryonic development by demethylating DNA. The effects of folic acid and vitamin B12 were tested to determine if they rescued regeneration from the potential effects of BPA, as these dietary compounds are thought to restore DNA methylation in mouse model systems. Preliminary research showed that BPA slowed regeneration in both anterior and posterior regeneration. Subsequently, the effects of BPA on morphology was compared using bright field and scanning electron microscopy (SEM), and potential effects on mitosis using confocal laser scanning microscopy (Click -It Edu® Cell Proliferation kit). Lower rates of cell proliferation were observed in BPA treated specimens, while subsequent exposure to folic acid or seawater (“rescue” treatments) appeared to restore mitosis rates to that of the controls. These results suggest that BPA disrupts regeneration by inhibiting mitosis, but also, that these effects may be reversed in early blastema formation by exposing the worms to a different environment

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https://scholar.acadiau.ca/islandora/object/theses:1458