Investigating the effect of xenobiotics on honeybee intestinal stem cell proliferation

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Cordelia Sackey-Mensah (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Olav Rueppell

Abstract: Over the past decades, the number of managed honeybee colonies in the United States has been declining. One hypothesis proposed to explain the decline is that exposure to xenobiotics might affect bee health without killing the bees directly. The gut is important to bee health because it functions as the first physical barrier after honeybees ingest xenobiotics. My research investigated the proliferation rate of intestinal stem cells (ISCs) as a biomarker of honeybee health after bees were exposed to 12 relevant xenobiotics. The study sought to determine whether the xenobiotics showed sub-lethal effects on ISC proliferation. I hypothesized that xenobiotics affect ISC proliferation at concentrations that do not significantly affect mortality. I studied acute and latent effects of selected xenobiotics and one combination of xenobiotics on honeybee lifespan and ISC proliferation. Except for a few xenobiotics, I found that most xenobiotics did not show ISC proliferation effects. Specifically, a high but sub-lethal concentration of hydroxytetracycline decreases proliferation, while tau-fluvalinate only decreases ISC proliferation at lethal doses. On the other hand, low concentrations of methoxyfenozide increased proliferation without any mortality effects. Thus, I identified several xenobiotic that have an effect on ISC proliferation. My results demonstrate sub-lethal effects of xenobiotics in a novel, health-relevant context but suggest that ISC proliferation is not a general honeybee health indicator. My study does not support a central role of the gut physiology in the recent health declines but cannot rule out specific effects that contribute to the general decline in honeybee health.

Additional Information

Publication
Thesis
Language: English
Date: 2012
Keywords
Fluvalinate, Honeybee, Intestinal stem cells, Methoxyfenozide, Tetracycline, Xenobiotics
Subjects
Honeybee $x Effect of chemicals on
Honeybee $x Metabolism
Xenobiotics $x Metabolism

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