We have finally come to the last lab of the school year! 😥 It is amazing to see how far we have come! Our lab studied Wolbachia in insects. I have never heard about Wolbachia until this lab, and was surprised to find out how common Wolbachia is in insects all around us!
Wolbachia is genus of bacteria that infects mostly arthropods and some nematodes. Wolbachia can be transmitted horizontally or vertically from parent to offspring in the female’s eggs. Something I found very interesting, is Wolbachia’ special ability to alter the sex of its host, which has given Wolbachia an advantage for reproducing. Altering the sex of its host gives Wolbachia an advantage because Wolbachia can only be passed down to offspring by females; males cannot pass down Wolbachia to their offspring. Infected females can only be only successfully reproduce with males that are infected with the same strain of Wolbachia bacteria. The sex ratio distortion may have a negative impact on the host population because with a large female to male ratio, it can be presumed that some females may not be able to mate and reproduce.
While researching, I learned that Wolbachia is safe for humans and animals and is being studied for its properties that will help kill viruses in mosquitoes and stop viruses from spreading to people. Scientists are conducting studies on Wolbachia to help eliminate Degnue fever! Click here to learn more about Wolbachia’s role in fighting Dengue fever.
The purpose of this lab was to conduct a DNA analysis to determine if an insect is infected by Wolbachia. We started by collecting anthropods and bringing them to the lab in vials that contained alcohol, and placed them in the freezer. Michelle and I shared an ant sample and collected its reproductive parts by crushing the ant’s abdomen. We had to then separate a segment of DNA from the rest of the bug. We then used the PCR machine to replicate segments of DNA.
Watch the video below to see how PCR works!
We used gel electrophoresis, a process that uses electricity to separate segments of DNA, to compare the samples to a ladder and positive control to see if Wolbachia DNA was present. If no Wolbachia was present, then there would be one mark shown on the gel. If the insect DNA sample did contain Wolbachia, then a second mark would appear. The ants that Michelle and I tested were negative for Wolbachia. Insects were collected from Burlingame, Brisbane, San Carlos, and Palo Alto. 4 of the insects contained Wolbachia, which mainly came from San Carlos! Mrs. Girard said that our class had the most insects with Wolbachia compared to years past, which most likely means that Wolbachia is infecting larger populations.
Aside from learning about Wolbachia, this lab allowed us to practice different biotechnology tools. I enjoyed using various biotech skill in this lab such as micropipetting, PCR, and gel electrophoresis. I PCR includes several steps, but my lab group and I made sure to work at the same pace to ensure that we were all on track! felt a little rusty picking up a micropipette again, but I was very excited to use it! This lab was very focussed on precision, so before we used to micropipette, we asked our AP Bio teammates to double check the measurements. My favorite step is the gel electrophoresis process because it is awesome to compare the different strains of DNA against one another!
This lab was so much fun and it reflects the entire dynamic of AP Biology class this year. It was awesome to look back and see how much expirience I have gained because of this class! I am very excited for labs in college, but I will definitely miss the fun, engaging, and safe space of the AP Biology classroom.