Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czechia.
Faculty of Science, University of South Bohemia, Ceske Budejovice, Czechia.
Front Cell Infect Microbiol. 2023 Jan 9;12:1081666. doi: 10.3389/fcimb.2022.1081666. eCollection 2022.
In addition to being vectors of pathogenic bacteria, ticks also harbor intracellular bacteria that associate with ticks over generations, aka symbionts. The biological significance of such bacterial symbiosis has been described in several tick species but its function in is not understood. We have previously shown that ticks are primarily inhabited by a single species of symbiont, , an intracellular bacterium that resides and reproduces mainly in the mitochondria of ovaries of fully engorged females. To study the functional integration of into the biology of , an -depleted model of ticks was sought. Various techniques have been described in the literature to achieve dysbiosed or apo-symbiotic ticks with various degrees of success. To address the lack of a standardized experimental procedure for the production of apo-symbiotic ticks, we present here an approach utilizing the membrane blood feeding system. In order to deplete from ovaries, we supplemented dietary blood with tetracycline. We noted, however, that the use of tetracycline caused immediate toxicity in ticks, caused by impairment of mitochondrial proteosynthesis. To overcome the tetracycline-mediated off-target effect, we established a protocol that leads to the production of an apo-symbiotic strain of , which can be sustained in subsequent generations. In two generations following tetracycline administration and tetracycline-mediated symbiont reduction, was gradually eliminated from the lineage. Larvae hatched from eggs laid by such -free females repeatedly performed poorly during blood-feeding, while the nymphs and adults performed similarly to controls. These data indicate that represents an integral component of tick ovarian tissue, and when absent, results in the formation of substandard larvae with reduced capacity to blood-feed.
除了作为病原菌的载体外，蜱虫还携带与蜱虫世代相关的内共生菌，即共生菌。这种细菌共生的生物学意义在几种蜱虫中已经被描述，但在蜱虫中的功能尚不清楚。我们之前已经表明，蜱虫主要被一种共生菌，即一种主要存在于卵巢中线粒体中并在其中繁殖的内共生菌所占据。为了研究 与 生物学功能的整合，我们寻求了一种缺乏 的 蜱虫模型。文献中已经描述了各种技术来实现具有不同程度成功的失调或无共生蜱虫。为了解决缺乏标准化的无共生蜱虫生产实验程序的问题，我们在这里提出了一种利用 膜血食系统的方法。为了从卵巢中耗尽 ，我们在饮食血液中补充了四环素。然而，我们注意到，四环素的使用会立即导致蜱虫中毒，这是由于线粒体蛋白质合成受损引起的。为了克服四环素介导的脱靶效应，我们建立了一种方案，导致产生一种无共生的 菌株，可以在随后的几代中维持。在四环素给药和四环素介导的共生体减少后的两代中， 逐渐从谱系中消除。由这种无 的雌虫产下的卵孵化的幼虫在吸血时表现不佳，而若虫和成虫的表现与对照相似。这些数据表明， 是蜱虫卵巢组织的一个组成部分，当它不存在时，会导致形成标准较低的幼虫，其吸血能力降低。
