The Effect of Environmental Changes of Food on Apoptosis in Zebrafish Ovarian Tissue

Apoptosis is the process of programmed cell death. B-cell CLL/lymphoma 2 (Bcl-2) is a well-studied gene that regulates cell death by acting as an inhibitor of apoptosis. The purpose of this experiment was to study the role of Bcl-2 in regulating cell death in the ovaries of zebrafish (Danio rerio). The hypothesis of the experiment was that if the intake of food that a zebrafish consumes is decreased, then apoptosis would increase in the ovarian tissues because the fish would not be receiving its normal nutrient intake. As a control, one group of fish was fed once every day. In contrast, the experimental group was fed once every other day. There were three fish in both the experimental and control group. Using standard feeding practices, we fed the zebrafish prescribed amounts of food at each feeding. The amount of food (in grams) was consistent from feeding to feeding. The length of the experiment was one week and the fish were dissected at the end of the experiment. The ovary tissue from the fish was collected and Bcl-2 levels were monitored using quantitative polymerase chain reaction (q-PCR) analysis.  The q-PRC results suggested that decreasing the intake of food intake results in reduction of Bcl-2 levels. These data suggest that there is not a normal amount of gene to inhibit apoptosis of the ovarian tissue, thus supporting our hypothesis of a decrease in the Bcl-2 gene expression in response to decreased food intake suggesting programmed cell death plays a role in fish responses to environmental conditions.