Poster abstracts
Poster number 71 submitted by Rachel Morris
Guardians of nutrient flow: transcriptomic insights into transporter interference in the tsetse–Wigglesworthia symbiosis
Rachel A. Morris (Department of Biology, West Virginia University), Rita V.M. Rio (Department of Biology, West Virginia University)
Abstract:
Membrane transporters uphold nutritional symbioses by mediating metabolite exchange. Tsetse flies, the primary vector of African trypanosomes, also harbor an obligate bacterial mutualist, Wigglesworthia glossinidia. These Wigglesworthia symbionts, harbored within bacteriocytes that comprise a bacteriome, provide B vitamins missing from the host’s strict vertebrate blood diet. Tsetse reciprocate by providing proteinaceous amino acids to the mostly auxotrophic Wigglesworthia. This metabolite exchange requires precise regulation, especially during metabolically intensive states (i.e., reproduction, trypanosome infection, and development), with disruption leading to negative fitness costs. Here, we characterize three tsetse proton-coupled amino acid transporters (SLC36 family) highly expressed within bacteriocytes: GMOY000882, GMOY008504, and GMOY012047. Due to their enrichment within bacteriomes, we hypothesize that these transporters are critical for stability of the symbiosis, given their predictive proline substrate. Wigglesworthia cannot synthesize proline, the major energy source for ATP production within tsetse. A nutrient reciprocation based on proline and vitamin B6 supply by tsetse and Wigglesworthia, respectively, underpins the association. To test transporter function, we used dsRNA-mediated knockdown of GMOY012047 followed by RNAseq analysis of bacteriome tissue to assess knockdown efficacy and transcriptomic changes relative to controls. This, combined with binding-based predictions of substrate specificity and expression profiles across the tsetse lifecycle, begins to reveal how SLC36 transporters shape bacteriocyte nutrient flux. Identifying and functionally characterizing these transporters provides insight into the obligate tsetse-Wigglesworthia metabolic integration. These discoveries highlight potential novel molecular targets for disrupting tsetse populations, which would also reduce the prevalence of trypanosome transmission.
Keywords: Amino Acid Transporters, Symbiosis , RNA Interference