Wolbachia Response to Insulin Signaling and Nutritional Status of the Drosophila Melanogaster Host

Authors

Moises CamachoFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biology

First Advisor's Name

Laura Serbus

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Matthew DeGennaro

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Mauricio Rodriguez-Lanetty

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Jamie Theobald

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Timothy Allen

Fifth Advisor's Committee Title

Committee member

Keywords

Drosophila, Wolbachia, Insulin, Receptor, Yeast, RNAi, Titer

Date of Defense

11-1-2022

Abstract

Wolbachia pipientis is an endosymbiotic bacterium that occupies the cells of many insects and arthropods in nature. In Drosophila, Wolbachia endosymbionts rely exclusively on maternal transmission for their spread in host populations. Thus, colonization of maternal germline cells is critical to the success of Wolbachia. Our lab previously found that Wolbachia colonization of developing egg cells is drastically affected by host diet and insulin signaling. My dissertation project has expanded our understanding of endosymbiont infection mechanisms by analyzing dietary signaling effects on Wolbachia in oogenesis. Initial comparison of dietary sweet tastants vs. dietary sugars showed that germline Wolbachia respond to glucose-containing sugar molecules. The study also indicated that oocyte Wolbachia load is determined independently of both oocyte size and ovary size. Optimization of staining procedures enabled collection of select timepoints across development by confocal fluorescence microscopy, providing a snapshot of Wolbachia colonization across oogenesis. The major finding that Wolbachia abundance in late-stage germline cells is especially sensitive to host dietary signaling, relative to earlier stages of oogenesis. Analysis of germline insulin receptors created a larger context for this finding, by identifying alternate strategies for germline stem cell regulation of Wolbachia load as compared to later stage germline cells. The data also indicated that systemic insulin signaling counteracts the function of germline insulin receptors, to ultimately suppresses germline Wolbachiacolonization. The distinction of systemic nutritional signaling effects from local germline responses is important for understanding germline colonization, and for future studies analyzing the dynamics of Wolbachia migration vs. replication as the basis for infection changes.

Identifier

FIDC010964

Previously Published In

CHAPTER II

Camacho M, Oliva M, Serbus LR. Dietary saccharides and sweet tastants have differential effects on colonization of Drosophila oocytes by Wolbachia endosymbionts. Biol Open. 2017 Jul 15;6(7):1074-1083. doi: 10.1242/bio.023895.

CHAPTER III

Christensen S, Camacho M*, Sharmin Z*, Momtaz AJMZ, Perez L, Navarro G, Triana J, Samarah H, Turelli M, Serbus LR. Quantitative methods for assessing local and bodywide contributions to Wolbachia titer in maternal germline cells of Drosophila. BMC Microbiol. 2019 Sep 3;19(1):206. doi: 10.1186/s12866-019-1579-3. *Contributed equally to this work.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Camacho, Moises, "Wolbachia Response to Insulin Signaling and Nutritional Status of the Drosophila Melanogaster Host" (2022). FIU Electronic Theses and Dissertations. 5149.
https://digitalcommons.fiu.edu/etd/5149