Tsetse flies (Glossina spp.) transmit parasitic African trypanosomes (Trypanosoma spp.), including Trypanosoma congolense, which causes animal African trypanosomiasis (AAT). AAT detrimentally affects agricultural activities in sub-Saharan Africa and has negative impacts on the livelihood and nutrient availability for the affected communities. After tsetse ingests an infectious blood meal, T. congolense sequentially colonizes the fly’s gut and proboscis (PB) organs before being transmitted to new mammalian hosts during subsequent feedings. Despite the importance of PB in blood feeding and disease transmission, little is known about its molecular composition, function and response to trypanosome infection. To bridge this gap, we used RNA-seq analysis to determine its molecular characteristics and responses to trypanosome infection. By comparing the PB transcriptome to whole head and midgut transcriptomes, we identified 668 PB-enriched transcripts that encoded proteins associated with muscle tissue, organ development, chemosensation and chitin-cuticle structure development. Moreover, transcripts encoding putative mechanoreceptors that monitor blood flow during tsetse feeding and interact with trypanosomes were also expressed in the PB. Microscopic analysis of the PB revealed cellular structures associated with muscles and cells. Infection with T. congolense resulted in increased and decreased expression of 38 and 88 transcripts, respectively. Twelve of these differentially expressed transcripts were PB-enriched. Among the transcripts induced upon infection were those encoding putative proteins associated with cell division function(s), suggesting enhanced tissue renewal, while those suppressed were associated with metabolic processes, extracellular matrix and ATP-binding as well as immunity. These results suggest that PB is a muscular organ with chemosensory and mechanosensory capabilities. The mechanoreceptors may be point of PB-trypanosomes interactions. T. congolense infection resulted in reduced metabolic and immune capacity of the PB. The molecular knowledge on the composition and putative functions of PB forms the foundation to identify new targets to disrupt tsetse’s ability to feed and parasite transmission.

采采蝇（舌蝇属）发射寄生非洲锥虫（锥虫属物种），包括刚果锥虫，这会导致动物非洲锥虫病（AAT）。AAT有害地影响了撒哈拉以南非洲的农业活动，并对受影响社区的生计和营养供应产生了负面影响。采采蝇摄入传染性血粉后，T。共犯先将果蝇的肠道和长鼻（PB）器官定殖，然后在随后的进食期间将其传播给新的哺乳动物宿主。尽管PB在血液供应和疾病传播中很重要，但对其分子组成，功能和对锥虫感染的反应知之甚少。为了弥合这一差距，我们使用RNA-seq分析来确定其分子特征和对锥虫感染的反应。通过将PB转录组与整个头部和中肠的转录组进行比较，我们确定了668个富含PB的转录本，这些转录本编码与肌肉组织，器官发育，化学感觉和甲壳质-表皮结构发育相关的蛋白质。此外，PB中还表达了编码假定的机械感受器的转录物，该监测器在采采蝇喂养期间监测血流并与锥虫相互作用。PB的显微镜分析揭示了与肌肉和细胞相关的细胞结构。感染Ť。congolense分别导致38和88个转录本的表达增加和减少。这些差异表达的转录物中有十二个富含PB。在感染后诱导的转录本中，有编码与细胞分裂功能相关的假定蛋白的转录本，表明组织更新增强，而受抑制的转录本则与代谢过程，细胞外基质，ATP结合以及免疫力有关。这些结果表明PB是具有化学感觉和机械感觉能力的肌肉器官。机械感受器可能是PB-锥虫相互作用的关键。Ť。共犯感染导致PB的代谢和免疫能力降低。关于PB的组成和推定功能的分子知识为确定破坏采采蝇进食和寄生虫传播能力的新靶标奠定了基础。