Abstract: “Disinfection By-Products (DBPs) are compounds which are produced during the water disinfection process. Currently, there are many DBPs that are unregulated by the U.S Environmental Protection Agency due to a lack of current research studies. Humans and other animals can be exposed to DBPs through inhalation, ingestion, and dermal absorption. Iodoacetic Acid (IAA), one of the current DBPs that goes unregulated has high cytotoxicity and genotoxicity in animals. There are many studies that have linked IAA exposure to developmental dysfunctions but not for female processes. In this study, whether IAA exposure has toxic effects on mouse oocyte maturation will be explored. In vitro, we show that IAA exposure caused abnormal spindle assembly and chromosome misalignment. We also found out that IAA exposure increased the Reactive Oxygen Species (ROS) levels in oocytes; this indicates that IAA treatment could induce oxidative stress in oocytes. Naturally, ROS is formed as a byproduct of everyday metabolism of oxygen which has important roles in initiating biologically processes and homeostasis. Concurrently, an increase in H2AX intensity showed that DNA damage was also elevated in the nuclei of IAA exposed mouse oocytes.”
East Central IL ACS Undergraduate Research Conference
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Great presentation! What statistical tests did you use to investigate your results of IAA exposure compared to the control?
Hi Shannon,
Thank you! For both the control and experimental groups, GraphPad Prism software was used where a Student’s unpaired two-tailed t-test was performed to compare the two groups. For each group, there were 3 replicates where ANOVA was used to compare each replicate.
Best,
Royal Shrestha
Hi Royal,
Great job! I have a few questions:
– Since GVBD is the first upstream process that you saw being disrupted, can you say that this is where the main effect is happening and the downstream effects are because of this deficient step? Or does the IAA continue to affect subsequent steps as well? How would you verify this?
– How do you plan to track these processes in in vivo systems?
Thanks!
Joe
Hi Joseph,
Great questions! While we can’t say the lower GVBD is where the main effect is happening, we are certain that it is a significant change in response to IAA. We tested many oocytes in over 33 mice and the GVBD was the most noticeable phenotype change. Our speculation at the time was further supported by the lower polar body extrusion on the same slide. As polar body extrusion is a sign that meiosis happened successfully, the fact that there were less polar body extrusions supported our GVBD speculation because without GVBD, meiosis comes to a halt. Our experiments, more specifically, showed at which stage in meiosis, the oocytes particularly arrest at.
As for in vivo systems which is our next goal, we are currently researching different meiosis markers we can use.
Best
Royal Shrestha