Bruzzese Daniel J, Gstöttenmayer Fabian, Weiss Brian L, Khalil Hager, Mach Robert, Abd-Alla Adly M M, Aksoy Serap
Res Sq. 2025 Aug 25:rs.3.rs-7295611. doi: 10.21203/rs.3.rs-7295611/v1.
Tsetse ( spp.) are vectors of African trypanosomes, the causative agents of Human and African Animal trypanosomiases, diseases that remain significant medical and socioeconomic challenges in sub-Saharan Africa. In addition to trypanosomes, tsetse harbor both obligate and facultative symbiotic bacteria that can influence vector competence and reproductive biology. One such facultative symbiont, , infects several tsetse species within the subgroup. In ( ), the strain Gff induces a trypanosome-refractory phenotype and negatively impacts reproductive fitness by reducing female fecundity. However, the mechanisms behind these -derived phenotypes remain poorly understood. Here, we report successful cultivation of Gff and present complete genomes from three sources: cultured Gff and Gff isolated from both laboratory-maintained and wild-caught (Uganda) flies. Comparative genomic analyses revealed a high degree of similarity in gene content and synteny among these Gff samples, confirming that they represent isolates of the same strain. Phylogenomic analyses placed Gff within the clade. The Gff genome is highly dynamic, containing numerous mobile genetic elements. Additionally, annotations indicate that Gff relies on its host for both lipids and carbohydrates and produces several toxins, all of which could be implicated in the observed trypanosome refractory phenotype. Finally, comparative transcriptomic analysis of Gff from host hemolymph versus culture provided insights into potential factors relevant to host-symbiont interactions. Our findings provide a foundation for understanding the nutritional dialogue between Gff and its host and identify symbiotic products that may contribute to trypanosome resistance. Furthermore, the establishment of an culture system for Gff represents a significant resource for future functional studies with potential implications for vector control.
采采蝇（舌蝇属）是非洲锥虫的传播媒介，而非洲锥虫是人类和非洲动物锥虫病的病原体，这些疾病在撒哈拉以南非洲仍然是重大的医学和社会经济挑战。除了锥虫外，采采蝇还携带专性和兼性共生细菌，这些细菌会影响传播媒介能力和生殖生物学。一种这样的兼性共生菌，即Wolbachia，感染了subgroup亚组内的几种采采蝇物种。在Glossina morsitans centralis（G.m.c.）中，Wolbachia菌株wGmmGff诱导了一种对锥虫难治的表型，并通过降低雌性繁殖力对生殖适应性产生负面影响。然而，这些Wolbachia衍生表型背后的机制仍知之甚少。在这里，我们报告了wGmmGff的成功培养，并展示了来自三个来源的完整基因组：培养的wGmmGff以及从实验室饲养和野生捕获（乌干达）的G.m.c.苍蝇中分离出的wGmmGff。比较基因组分析揭示了这些wGmmGff样本在基因含量和共线性方面的高度相似性，证实它们代表同一菌株的分离株。系统发育基因组分析将wGmmGff置于Wolbachia进化枝内。wGmmGff基因组高度动态，包含众多移动遗传元件。此外，注释表明wGmmGff在脂质和碳水化合物方面都依赖其宿主，并产生几种毒素，所有这些都可能与观察到的锥虫难治表型有关。最后，对来自宿主血淋巴的wGmmGff与体外培养的wGmmGff进行比较转录组分析，为与宿主 - 共生体相互作用相关的潜在因素提供了见解。我们的研究结果为理解wGmmGff与其宿主之间的营养对话奠定了基础，并确定了可能有助于抵抗锥虫的共生产物。此外，建立wGmmGff的培养系统代表了未来功能研究的重要资源，对病媒控制具有潜在影响。
