Friday, August 16, 2019

URSP Student Colin Moore Studies the Affects of AZT on Zebrafish

I am studying how a chemical called Atrazine (ATZ) affects sexual development in Zebrafish. I originally heard about this issue online when male African Clawed Frogs, exposed to ATZ, developed female characteristics such as the growth of ovaries or even viability as an induced female. It is hypothesized that this feminization is caused by exposure to ATZ when these anamniotes (fish and amphibians) are in their embryonic stage. Therefore, I decided to test this on Zebrafish to get a better understanding of how this chemical alters their sexual development.
            I monitor the pH, ammonia, nitrates, nitrites, and temperature of the fish tank daily. I feed the fish twice a day and I monitor the water levels constantly. I must ensure that the water level stays consistent and flowing, so that none of the fish will suffer from hypoxia. I must also look for, and remove, any deceased fish so that their decomposition does not harm any others. I counted the number of alive males and females per treatment and found that there was a skewed ratio in the ATZ group, with 11 females to 7 males. However, the Zebrafish still have another week or two before they will be fully developed so this ratio will be recounted and analyzed at that time. I set aside a batch of fish embryos in February for immunofluorescence and I am currently in the process of detecting aromatase (indicator for estrogen) expression. After cursory analysis, there was increased aromatase expression in the hearts of the ATZ-treated group, but this process is still on-going. By comparing the results from both tests, we can obtain a better understanding of how ATZ feminizes anamniotes and to what extent.