Discipline: Ecology Environmental and Earth Sciences
Joshua Pettibon - Texas A&M University - Commerce
Co-Author(s): Dr. Elizabeth Ottesen, University of Georgia, Athens, GA; Kara Tinker University of Georgia, Athens, GA
The cockroach hind gut contains a highly diverse microbial community. Previous research done by the Ottesen laboratory suggests that the hindgut community of the American cockroach, Periplaneta Americana, exhibits low individual-to-individual variability and does not change substantially in response to dietary shifts. In this project, research was done to evaluate gut microbial diversity among different cockroach species, as well as to test how co-housing and isolation influence how change in diet impacts gut bacterial assemblage within Periplaneta americana.
To test how cockroach hindgut communities vary between species, eleven species of cockroaches were obtained and their hindguts removed. DNA was extracted from the hindguts using Omega Bio-Tek’s E.Z.N.A. Bacterial DNA Kit. The DNA was amplified and marked with a genetic bar code using two-step PCR technique. After confirming the presence of DNA with a nanodrop, the DNA was purified and sequenced. The resulting data was then analyzed and graphed using the programs Mothur and R. It was discovered that different cockroach species possess different gut microbial communities, and that these communities cluster by host species and family on a Bray-Curtis dissimilarity graph. This indicates that cockroach gut microbiota cluster based on host species, but show less dissimilarity between closely related cockroach species and greater dissimilarity among cockroach families.
To test the effects of diet shifts on Periplaneta Americana gut communities under different housing conditions, six groups of twenty cockroaches were housed in plastic aquariums and sixty individuals in cups. After a strict diet of dog food, butter, tuna, bran cereal, sugar, or nothing but water for fourteen days, the cockroach hindguts were extracted and processed with a similar method as described before. Future work still needs to be done to analyze the results from the diet experiment. Also in the future, more species of cockroaches will be processed to gain a full spectrum of the bacteria communities present between cockroach species and among different cockroach families.
Funder Acknowledgement(s): Special thanks to The University of Georgia's microbiology department for their support. Also, thanks to the National Science Foundation for providing funding through grant DBI-1460671.
Faculty Advisor: Dr. Elizabeth Ottesen, firstname.lastname@example.org
Role: For this project I set up the experiments as described by my mentor, maintained the cockroach colonies, and preformed cockroach dissections. I also preformed DNA extractions, DNA amplifications using PCR, and DNA concentration testing using a nanodrop; as well as determined the presence of DNA using gel electrophoresis. Additionally, I kept physical and digital records of the experiment, input data into the computer, and graphed the data using program R. I also partially interpreted and analyzed the portion of data I graphed.