Purpose: To determine if insects and arachnids in the Bay Area contain the bacteria, wolbachia, in their DNA.
Wolbachia is a bacteria that is found in about 66% of all insects since discovered in the early 1900s. Wolbachia can cause feminization, decreased survival rates of offspring, and infertility in males. If a male host’s sperm is infected with the bacteria, when the sperm merges with an unaffected egg, the embryo is unable to develop. If an infected egg merges with an infected sperm, embryo development occurs normally and the bacterium is passed on. Wolbachia is being studied due to its effect on the success and population size of insects. Scientists have used Wolbachia to their advantage to decrease insect-born diseases such as malaria. Wolbachia is not present in other organisms such as mammals or molluscs and is most prevalent in insects and nematodes. Since Wolbachia feminizes the population, only females survive, which decreases the population size and fertility rate of helping to control the population.
1. DNA extraction: mash abdomen of insect and add lysis buffer into microfuge tube
2. PCR: *USED TO CLONE OR MULTIPLE TARGET DNA* add NaCl, mashed insect with lysis buffer, add isopropanol and TE/RNase buffer. Throughout the process, microfuge tube is centrifuged and pellet at the bottom of the tube is avoided.
3. gel electrophoresis: master mix, primer mix and PCR’d DNA is added in the sample well. Expected results for DNA containing Wolbachia will have two blurbs in the gel.
Results from the lab: 4/12 insects contained Wolbachia DNA in our class data (all were mostly from San Carlos uh oh)! This 33% rate does not compare to the 66% national rate, however we did have a small selecting range of the Bay Area. These results mean that 4 of the insects tested contained both insect and Wolbachia DNA, proof that the Wolbachia bacteria is largely spreading in the Bay Area, as the rate has jumped largely over the past 3 years. However, the other samples did not contain Wolbachia.
Reflection on the lab: I really enjoyed this lab! I liked that it incorporated almost all the skills we have learned this year such as DNA extraction, PCR and gel electrophoresis. I enjoyed the process of extracting DNA however I did not enjoy the PCR aspect because it is so tedious, precice and lenghty just for a small sample (found myself a little nervous completing this I didn’t want to mess it up whoopsie)! My favorite part was gel electrophoresis because I didn’t have to do too much myelf personally I just had to wait for the cute little DNA to travel through the gel and wait for the results (oh the agony!!). Wolbachia truly is whacky!
“Polymerase Chain Reaction.” Wikipedia. Wikimedia Foundation, 21 May 2017. Web. 23 May 2017.
Bordenstein, Seth R., Christine Brothers, George Wolfe, Michele Bahr, Robert L. Minckley, Michael E. Clark, Jennifer J. Wernegreen, Sarah R. Bordenstein, William S. Reznikoff, and John H. Werren. “Using the Wolbachia Bacterial Symbiont to Teach Inquiry-Based Science: A High School Laboratory Series.” The American Biology Teacher. University of California Press Journals, 01 Oct. 2010. Web. 23 May 2017.
“What Is Gel Electrophoresis?” Facts. The Public Engagement Team at the Wellcome Genome Campus, 25 Jan. 2016. Web. 23 May 2017.