Pitx1 Enhancer Lab Report

The Use of PCR and Gel Electrophoresis to Examine the Pitx1 Enhancer Region in the Stickleback Fish of Big Lake

Hypothesis:

Due to selective pressures in a freshwater environment, the stickleback fish in Big Lake will not have pelvic spines due to an insertion mutation in the Pitx1 enhancer region.

Rationale:

Since these stickleback fish are found in Big Lake, which is a freshwater lake that does not experience a marine environment, they will not have pelvic spines due to the specific selective pressures they experience. In Big Lake, the calcium levels is 14ueqv/L, which is much lower than the calcium levels found in a marine environment. This can result in less bone growth, and a lack of pelvic spine found in the stickleback fish. There

In the stickleback fish found in Big Lake (seen in slot #4 and #5) are about 1400 base pairs long. By using PCR, we were successfully able to isolate the Pitx1 enhancer region in the marine control, and both stickleback fish in Big Lake. The sterile water used in the experiment was not contaminated, as seen in slot #6 of the gel electrophoresis, which means the results of the experiment should be accurate and without any contamination. There is a deletion in the Pitx1 enhancer region of the stickleback fish found in Big Lake, since the Pitx1 enhancer region is approximately 117 base pairs shorter than the marine

In my hypothesis, I state that the stickleback fish would not have a pelvic spine caused by an insertion mutation in the Pitx1 enhancer region. According to the gel, the stickleback fish in Big Lake do not have the pelvic spine due to a deletion mutation found in the Pitx1 enhancer region. This can be further proved by the phenotype of the fish found in Big lake. The stickleback fish found in Big Lake (seen in figure 2) is smooth across the bottom, with no pelvic spine present. This proof supports the results of the gel