Spiroplasma effects on Tsetse Flies

采采蝇是致病性非洲锥虫的主要媒介，导致社会- 具有经济破坏性的疾病。采采子通过腺营养性胎生繁殖，并依赖于 它们的互惠共生内生菌Wigglesworth产生的营养物质。除了威格尔斯沃西亚， 有些采采子物种可寄生沃尔巴克氏菌、兼性苏打和螺旋体。我们的 对沃尔巴克氏菌的研究表明，感染该细菌会影响男性的生殖生理 并导致细胞质不亲和性。在这里，我们讨论采采族之间的分子对话。 以及新发现的内共生体螺旋体，这种螺旋体在其他节肢动物中会引起各种 生殖异常。螺旋体只感染棕榈亚属中的采采种， 包括粘虫(Glossina fuscipes，GFF)，这是一种多产的疾病媒介。虽然它对采采业的影响 繁殖未知，螺旋体诱导对锥虫感染的抵抗力增强 实验室。我们提出了两个研究目标，旨在剖析螺旋体感染的影响 在1)雄性生殖生理与交配成功有关，2)雌性繁殖力和3)采采率- 螺旋体对话，因为它与采采族的媒介能力有关。 目的1.螺旋体对男性生殖健康的影响。我们假设螺旋体 雄性采采物感染影响1)MAG和睾丸基因表达，2)精原细胞 成分，以及3)精子适合性。为了验证我们的假设，我们将1)建立感染螺旋体的 和未感染的GFF系，2)比较分析SPI-2的性腺基因表达。 与SPI雄性相比，3)测定与SPI-或SPI交配的雌性的精荚含量 男性，以及4)评估螺旋体对精子适应性的影响。 目的2.螺旋体对寄生虫传播动力学的影响。我们假设 螺旋体感染通过a)诱导宿主免疫间接降低采采族的媒介能力 响应或b)限制寄生虫的营养可获得性，或2)通过表达抗 锥虫产品。为了验证我们的假设，我们将：1)分析GffSpi的全球基因表达- 和GffSpi个体，2)检测感染和未感染GffSpi锥虫的营养状况。 和GffSpi个体，以及3)测试培养的螺旋体的胰酶溶解活性。 加强对采采叶-螺旋体共生的认识将为 阐明不同生殖内共生菌影响寄主生理的机制。 我们的结果将具有翻译意义，因为减少采采子繁殖力或媒介 能力将直接减少疾病传播。最后，我们的结果将是相关的， 适用于其他医学和农业上重要的昆虫，在这些昆虫中存在共生微生物。

Tsetse flies are prominent vectors of pathogenic African trypanosomes, which cause socio- economically devastating diseases. Tsetse reproduce by adenotrophic viviparity and depend upon nutrients produced by their mutualist endosymbiont, Wigglesworthia. In addition to Wigglesworthia, some tsetse species can harbor parasitic Wolbachia and facultative Sodalis and Spiroplasma. Our studies on Wolbachia indicate that infection with the bacterium affects male reproductive physiology and induces Cytoplasmic Incompatibility. Here, we address the molecular dialogue between tsetse and its newly discovered endosymbiont Spiroplasma, which in other arthropods causes various reproductive abnormalities. Spiroplasma infects only tsetse species within the Palpalis subgenus, including Glossina fuscipes fuscipes (Gff), a prolific disease vector. Although its effects on tsetse reproduction are unknown, Spiroplasma induces enhanced resistance to trypanosome infection in the laboratory. We propose two research aims designed to dissect the impact of Spiroplasma infections on 1) male reproductive physiology related to mating success, 2) female fecundity, and 3) tsetse- Spiroplasma dialogue as it pertains to tsetse’s vector competence. Aim 1. Spiroplasma effects on male reproductive fitness. We hypothesize that Spiroplasma infections in male tsetse influence 1) MAG and testis gene expression, 2) spermatophore composition, and 3) sperm fitness. To test our hypothesis, we will 1) establish Spiroplasma infected and uninfected Gff lines, 2) perform comparative global gene expression analyses of gonads from Spi- versus Spi+ males, 3) determine spermatophore contents from the females mated with Spi- or Spi+ males, and 4) evaluate Spiroplasma effects on sperm fitness. Aim 2. Spiroplasma effects on parasite transmission dynamics. We hypothesize that Spiroplasma infections diminish tsetse’s vector competence 1) indirectly by a) inducing host immune responses or b) limiting nutrient availability for parasites, or 2) directly by expressing anti- trypanosomal products. To test our hypothesis, we will: 1) profile global gene expression from GffSpi- and GffSpi+ individuals, 2) determine nutritional status of trypanosome infected and uninfected GffSpi- and GffSpi+ individuals and 3) test cultivated Spiroplasma for trypanolytic activity. Enhanced knowledge about the tsetse-Spiroplasma symbiosis will provide a foundation to elucidate the mechanisms by which different reproductive endosymbionts influence host physiology. Our results will have translational implications, as reducing either tsetse fecundity or vector competence will directly reduce disease transmission. Finally, our results will be relevant and applicable to other medically and agriculturally important insects in which symbiotic microbes persist.