LE3 .A278 2020

2020

Gibson, Glenys

Acadia University

Bachelor of Science

Honours

Biology

Biology

While almost all polychaete species can regenerate, the physiology of regeneration and its regulation differs among taxa. Nereids, for instance, lose their regenerative abilities as they become sexually mature as a result of a decrease in brain-derived juvenile hormone, with some authors suggesting estradiol may affect maturation. Pygospio elegans (Spionidae), by contrast, reproduces both sexually and by architomy, which occurs as fragmentation followed by caudal (tail) and cephalic (head) regeneration. No endocrine influences on P. elegans regeneration or reproduction have been identified. Bispheno-A disrupts regeneration via mitosis inhibition and DNA methylation disruption, and as BPA is an estrogen mimic and a potent endocrine disruptor in vertebrates, this raises the question of whether BPA has similar endocrine-disrupting effects in polychaetes. To investigate whether estradiol affects nereid regeneration, if BPA exposure mimics the effects of estradiol, and whether potential effects in Alitta virens (Nereidae) differ from the known effects of BPA on P. elegans, I compared regenerate morphology between A. virens exposed to 1000 ng L-1 estradiol-17β, 3000 ng L¬1BPA, BPA+estradiol, or seawater (control), with parallel experiments on regeneration in P. elegans. No significant effects of BPA, estradiol, or their interaction were observed. Power to detect effects was reduced by sample size attrition due to infestation and by noise from the effects of infestation and of initial size on regenerate morphology.

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https://scholar.acadiau.ca/islandora/object/theses:3388