Bergmann Stella, Bohn Maja C, Dornbusch Susann, Becker Stefanie C, Stern Michael
Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany.
Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany.
Pathogens. 2023 Apr 5;12(4):558. doi: 10.3390/pathogens12040558.
In blood-feeding dipterans, olfaction plays a role in finding hosts and, hence, in spreading pathogens. Several pathogens are known to alter olfactory responses and behavior in vectors. As a mosquito-borne pathogen, Rift Valley Fever Virus (RVFV) can affect humans and cause great losses in livestock. We test the influence of RVFV infection on sensory perception, olfactory choice behavior and activity on a non-biting insect, , using electroantennograms (EAG), Y-maze, and locomotor activity monitor. Flies were injected with RVFV MP12 strain. Replication of RVFV and its persistence for at least seven days was confirmed by quantitative reverse transcription-PCR (RT-qPCR). One day post injection, infected flies showed weaker EAG responses towards 1-hexanol, vinegar, and ethyl acetate. In the Y-maze, infected flies showed a significantly lower response for 1-hexanol compared to uninfected flies. At days six or seven post infection, no significant difference between infected and control flies could be found in EAG or Y-maze anymore. Activity of infected flies was reduced at both time points. We found an upregulation of the immune-response gene, nitric oxide synthase, in infected flies. An infection with RVFV is able to transiently reduce olfactory perception and attraction towards food-related odors in , while effects on activity and immune effector gene expression persist. A similar effect in blood-feeding insects could affect vector competence in RVFV transmitting dipterans.
在吸血双翅目昆虫中，嗅觉在寻找宿主以及病原体传播方面发挥着作用。已知几种病原体可改变媒介昆虫的嗅觉反应和行为。作为一种蚊媒病原体，裂谷热病毒（RVFV）可感染人类并给家畜造成巨大损失。我们使用触角电图（EAG）、Y型迷宫和运动活动监测仪，测试了RVFV感染对一种非吸血昆虫感官知觉、嗅觉选择行为和活动的影响。给果蝇注射RVFV MP12毒株。通过定量逆转录PCR（RT-qPCR）确认了RVFV的复制及其至少持续七天的情况。注射后一天，受感染的果蝇对1-己醇、醋和乙酸乙酯的EAG反应较弱。在Y型迷宫实验中，与未感染的果蝇相比，受感染的果蝇对1-己醇的反应明显更低。在感染后第六天或第七天，在EAG或Y型迷宫实验中，受感染果蝇与对照果蝇之间不再有显著差异。在这两个时间点，受感染果蝇的活动都有所减少。我们发现受感染果蝇体内免疫反应基因一氧化氮合酶上调。RVFV感染能够暂时降低果蝇对与食物相关气味的嗅觉感知和吸引力，而对活动和免疫效应基因表达的影响持续存在。在吸血昆虫中出现类似效应可能会影响RVFV传播双翅目昆虫的媒介能力。
