Authors: Cooper Johnson
Mentors: John Chaston
Insitution: Brigham Young University
The main goal of this project is to determine the relationships between microbes in the microbiota of Drosophila and the activity rate of Drosophila at low temperatures. Previous research has already determined that the microbiota leads to changes in fly activity levels at normal temperatures (Schretter, 2019). Studying the relationship at low temperatures with the method I will outline below will help us to have a more holistic view of how the bacteria affect fly locomotion and behavior. This holistic understanding can open doors for other projects that study if manipulation of the microbiota could have a specific desired effect on the fly’s behavior, and it can help us understand how the microbiota’s impacts are affected by drastic changes in temperature. In this experiment we seek to determine how each of 41 different strains of bacteria affects fly activity at temperatures of approximately 17 degrees celsius using several different metrics to measure both locomotion and social behaviors. These metrics would be collected simultaneously by placing flies in a chamber for Drosophila Video Tracking (DVT), which would use a camera and tracking software to record the above-mentioned metrics on fly activity. Using so many different metrics allows us to have a more holistic view of the flies’ activity and to be able to better determine exactly how the bacteria are affecting the flies. In order to connect the data with the microbiota, the flies would be separated into 41 different experimental groups and each group would be “mono-associated” with one of the 41 different above-mentioned bacterial strains. Mono-association means that each of the fly eggs would be bleached, and then divided in groups, with each group being grown in an environment containing a specific type of bacteria. This means that each fly experimental group would have one species of bacteria in their microbiota, and therefore we can associate changes in fly behavior to the differences in the Drosophila microbiota. Having determined which bacteria affect the fly activity at low temperatures, we would use Metagenome-wide association to determine which bacterial genes are causing this change. Metagenome-wide association involves comparing the genomes of bacteria shown to cause changes in Drosophila activity in order to identify the similar protein-coding sequences that may be the causes of these changes in activity. To confirm the findings at that stage, the genes are expressed in a bacteria that doesn’t express them normally, and flies are analyzed to see if the changes in activity persist. If they do, we can safely say that the changes are due to that specific gene sequence. We expect that the mono-associated flies will show differences in activity level, because it has already been established in a previous study that the microbiota in the flies has a statistically significant effect on the activity level of the flies, meaning that the presence of certain bacterial cultures in the flies lead to a difference in activity. Therefore, if there is no difference in activity level, it is most likely due to the low temperatures, and it may then be necessary to perform the experiment again at different temperatures to determine at what point the temperature negates the effect caused by the bacteria present in the fly microbiota. We aim to study the relationship between the microbes present in the fly microbiota and their activity level at low temperatures and identify the mechanisms by which the microbes affect the fly activity level.