Functional differentiation of tsetse species microbiota

 描述（由申请方提供）：采采蝇（双翅目：舌蝇科）是非洲锥虫（布氏锥虫属）的周期性媒介。其是致命的人类非洲锥虫病（HAT）的病原体，以及野生和家养动物中的Nagana。采采蝇肠道微生物群由两种占优势的细菌组成：古老的专性互利菌，Wigglesophagia spp.，和舌侧索蜥已知采采蝇物种之间的载体能力不同，但微生物群如何影响这种变化仍然未被探索。一个普遍的偏见是，微生物群在不同的采采蝇物种中发挥着相同的功能作用。该提案通过确定采采蝇物种微生物群的功能差异并评估这些差异如何影响宿主发育，生殖输出和媒介能力来挑战这一信念。首先，已知的Wigglesophagia spp.，进一步研究了在Glossinamorsitans（Wgm）中所含的Wigglesophagia生物合成分支酸和下游叶酸的能力。将表征宿主发育、妊娠和锥虫挑战期间相关生物合成位点的转录谱，量化细菌组（容纳Wigglesophoria单一培养物的器官）内的叶酸丰度，并确定叶酸代谢破坏对采采蝇生物学和载体能力多个方面的影响。第二，代谢整合之间的Wigglesophoria和Sodalis相对于苯丙氨酸的生产将检查通过并发的两个共生体的转录谱。将进行中肠内苯丙氨酸丰度的靶向定量，并确定Sodalis苯丙氨酸生物合成对采采蝇适应性和对锥虫感染的易感性的影响。采采蝇微生物之间的这些代谢差异特别有趣，因为G。Morsitans是一种多产的锥虫载体， 和T.布氏杆菌亚种不能合成叶酸和苯丙氨酸，但采采蝇的发育需要这些物质。最后，下一代测序将被用来比较两个进化上不同的采采蝇物种，G。morsitans和G. brevipalpis，分别代表高和低载体能力的蝇种。这项资助提出的目标将确定共生体的代谢能力如何对采采蝇生物学和宿主载体能力的医学显著表型变异做出贡献。从应用的角度来看，采采蝇微生物群的操纵提供了扩大病媒控制的潜在途径，例如开发针对关键共生体介导的代谢过程的替代生物控制技术。

 DESCRIPTION (provided by applicant): Tsetse flies (Diptera: Glossinidae) are the cyclical vectors of African trypanosomes (Trypanosoma brucei spp.) which are the causative agents of fatal Human African Trypanosomiasis (HAT), and Nagana in wild and domesticated animals. The tsetse enteric microbiota consists of two dominant bacteria; the ancient obligate mutualist, Wigglesworthia spp., and the commensal Sodalis glossinidius. Vector competence is known to differ among tsetse species, but how the microbiota may influence this variation remains unexplored. A general preconception is that the microbiota performs identical functional roles within different tsetse species. This proposal challenges this belief by identifying functional differences in the microbiota of tsetse fly species and assessing how these may impact host development, reproductive output and vector competence. First, a known functional distinction between Wigglesworthia spp., the capability for chorismate and downstream folate biosynthesis by Wigglesworthia harbored within Glossina morsitans (Wgm), is further investigated. The transcriptional profiles of relevant biosynthetic loci during host development, pregnancy and trypanosome challenge will be characterized, folate abundance within bacteriomes (organs which house monocultures of Wigglesworthia) quantified, and the impact of folate metabolic disruption towards multiple facets of tsetse biology and vector competency determined. Second, metabolic integration between Wigglesworthia and Sodalis relative to phenylalanine production will be examined through concurrent transcriptional profiling of the two symbionts. Targeted quantification of phenylalanine abundance within midguts will be performed, and the impact of Sodalis phenylalanine biosynthesis towards tsetse fitness and susceptibility to trypanosome infections determined. These metabolic distinctions between the microbiota of tsetse species are particularly intriguing, given the fact that G. morsitans is a prolific vector of trypanosomes, and T. brucei subspp. are unable to synthesize folate and phenylalanine but require these for development within tsetse. Lastly, next generation sequencing will be used to compare the symbiont transcriptomes of two evolutionary divergent tsetse species, G. morsitans and G. brevipalpis, which represent fly species of high and low vector competence, respectively. The aims proposed in this grant will determine how symbiont metabolic capabilities contribute to tsetse biology and medically significant phenotypic variations in host vector competency. From an applied angle, the manipulation of the tsetse microbiota offers potential avenues to amplify vector control, such as the development of alternative biocontrol techniques targeting pivotal symbiont-mediated metabolic processes.