Abstract：
Tick infestations transmit various infectious agents and result in significant socioeconomic consequences. Currently, the primary focus of tick control efforts is identifying potential targets for immune intervention. In a previous study, we identified a highly conserved protein abundant in tick haemolymph extracellular vesicles (EVs) known as translationally controlled tumour protein (TCTP). We have found that native TCTP is present in various tissues of the Rhipicephalus haemaphysaloides tick, including salivary glands, midgut, ovary, and fat body. Notably, TCTP is particularly abundant in the tick ovary and its levels increase progressively from the blood-feeding stage to engorgement. When the TCTP gene was knocked down by RNAi, there was a noticeable delay in ovarian development, and the reproductive performance, in terms of egg quantity and survival, was also hindered. Our investigations have revealed that the observed effects in ovary and eggs in dsRNA-treated ticks are not attributable to cell death mechanisms like apoptosis and autophagy but rather to the reduction in the expression of vitellogenin (Vg1, Vg2, and Vg3) and ferritin (ferritin 1 and ferritin 2) proteins crucial for ovarian development and embryo survival in ticks. Additionally, phylogenetic analysis and structural comparisons of RhTCTP and its orthologues across various tick species, vertebrate hosts, and humans have shown that TCTP is conserved in ticks but differs significantly between ticks and their hosts, particularly in the TCTP_1 and TCTP_2 domains. Overall, TCTP plays a vital role in tick reproductive development and presents itself as a potential target for tick control in both humans and animals.
摘要：
蜱虫感染会传播各种感染因子，并导致重大的社会经济后果。目前,蜱虫控制工作的主要重点是确定潜在的免疫干预目标.在之前的研究中,我们在蜱血淋巴细胞外囊泡(EV)中发现了一种高度保守的蛋白,称为翻译控制肿瘤蛋白(TCTP).我们已经发现，天然TCTP存在于红毛蜱的各种组织中，包括唾液腺,中肠,子房,和肥胖的身体。值得注意的是,TCTP在蜱卵巢中特别丰富，其水平从血液喂养阶段到充血逐渐增加。当TCTP基因被RNAi敲低时，卵巢发育有明显的延迟，和生殖性能，就鸡蛋数量和存活率而言，也受到了阻碍。我们的研究表明，在dsRNA处理的蜱中观察到的卵巢和卵中的作用不是归因于细胞死亡机制，例如细胞凋亡和自噬，而是归因于卵黄蛋白原（Vg1，Vg2和Vg3）和铁蛋白（铁蛋白1和铁蛋白2）蛋白对蜱中的卵巢发育和胚胎存活至关重要。此外,RhTCTP及其直系同源物的系统发育分析和结构比较，脊椎动物寄主,人类已经证明TCTP在蜱中保守，但在蜱和它们的宿主之间有显著差异，特别是在TCTP_1和TCTP_2域中。总的来说,TCTP在蜱的生殖发育中起着至关重要的作用，并成为人类和动物控制蜱的潜在目标。
