chapter  9
16 Pages

Host and Symbiont Adaptations Provide Tolerance to BeneŒcial Microbes: Sodalis and Wigglesworthia Symbioses in Tsetse Flies

Introduction ............................................................................................................ 176 Genus Wigglesworthia Highlights ......................................................................... 176 Genus Sodalis Highlights ....................................................................................... 178 Tsetse Paratransgenesis Using Sodalis .................................................................. 180 Symbiont Transmission Biology and Generation of Wigglesworthia-Cured Tsetse ..................................................................................................................... 181 Symbiotic In¥uences on Parasitism and Tolerance to Wigglesworthia ................. 181 Tolerance of Tsetse to Sodalis ............................................................................... 184 Conclusion ............................................................................................................. 187 References .............................................................................................................. 187

Human African trypanosomiasis (HAT) is a fatal disease caused by the protozoan Trypanosoma brucei spp. and transmitted by the tsetse ¥y (genus Glossinidiae). Both male and female adult ¥ies are strict blood feeders during all developmental stages, and both sexes can transmit trypanosomes to a vertebrate host while feeding. Tsetse ¥ies also harbor two enteric microbes, the primary symbiont Wigglesworthia glossinidia and the secondary symbiont Sodalis glossinidius. In addition, some tsetse populations harbor a third microorganism that is related to parasitic Wolbachia pipientis (Figure 9.1). Both Wigglesworthia and Sodalis are members of γ-Proteobacteria closely related to the enteric microbes (Figure  9.2), while Wolbachia belongs to α-Proteobacteria. All three symbionts are thought to be important for host physiological functions.