Embrapa Agricultural Informatics, Campinas, Brazil.
Bolsista do CNPq (157460/2018-5), Programa de Pós-Graduação em Biotecnologia, Universidade Federal de Pelotas, Pelotas, Brazil.
Front Cell Infect Microbiol. 2020 Jan 21;9:477. doi: 10.3389/fcimb.2019.00477. eCollection 2019.
The success of cattle tick fixation largely depends on the secretion of substances that alter the immune response of the host. The majority of these substances are expressed by the parasite salivary gland and secreted in tick saliva. It is known that hosts can mount immune responses against ticks and bovine European breeds, and bovine industrial crossbreeds are more susceptible to infestations than are cattle. To identify candidates for the development of novel control strategies for the cattle tick , a salivary gland transcriptome analysis of engorged females fed on susceptible or resistant hosts was performed. Using RNA-Seq, transcriptomes were assembled and produced a total of 235,451 contigs with 93.3% transcriptome completeness. Differential expression analysis identified 137 sequences as differentially expressed genes (DEGs) between ticks raised on tick-susceptible or tick-resistant cattle. DEGs predicted to be secreted proteins include innexins, which are transmembrane proteins that form gap junction channels; the transporters Na/dicarboxylate, Na/tricarboxylate, and phosphate transporter and a putative monocarboxylate transporter; a phosphoinositol 4-phosphate adaptor protein; a cysteine-rich protein containing a trypsin inhibitor-like (TIL) domain; a putative defense protein 3 containing a reeler domain; and an F-actin-uncapping protein LRRC16A with a CARMIL_C domain; these genes were upregulated in ticks fed on tick-susceptible cattle. DEGs predicted to be non-secreted proteins included a small heat shock protein and the negative elongation factor B-like, both acting in a coordinated manner to increase transcript levels in the salivary glands of the ticks fed on tick-susceptible cattle; the 26S protease regulatory subunit 6B and another chaperone with similarity to calnexin, also upregulated in ticks fed on tick-susceptible cattle; an EF-hand calcium binding protein and a serine carboxypeptidase (), both involved in the blood coagulation cascade and upregulated in ticks fed on tick-susceptible cattle; and two ribosomal proteins, the 60S acidic ribosomal protein P2 and the 60S ribosomal protein L19. These results help to characterize cattle tick salivary gland gene expression in tick-susceptible and tick-resistant hosts and suggest new putative targets for the control of tick infestations, as those genes involved in the mechanism of stress response during blood feeding.
牛蜱的成功固定在很大程度上取决于改变宿主免疫反应的物质的分泌。这些物质中的大多数由寄生虫唾液腺表达，并分泌在蜱唾液中。已知宿主可以对蜱虫和欧洲牛品种产生免疫反应，而牛的工业杂交品种比牛更容易受到侵扰。为了确定开发新型牛蜱控制策略的候选物，对饱食于易感或抗性宿主的雌性唾液腺进行了转录组分析。使用 RNA-Seq，组装了转录组，共产生了 235451 个具有 93.3%转录组完整性的 contigs。差异表达分析鉴定出 137 个序列为在饲养于易感或抗性牛上的蜱之间差异表达基因 (DEGs)。预测为分泌蛋白的 DEGs 包括形成间隙连接通道的跨膜蛋白连接蛋白；转运蛋白 Na/dicarboxylate、Na/tricarboxylate 和磷酸盐转运蛋白和推定的单羧酸转运蛋白；磷酸肌醇 4-磷酸衔接蛋白；含有胰蛋白酶抑制剂样 (TIL) 结构域的富含半胱氨酸的蛋白；含有 reeler 结构域的推定防御蛋白 3；和具有 CARMIL_C 结构域的 F-肌动蛋白解帽蛋白 LRRC16A；这些基因在饲养于易感牛上的蜱中上调。预测为非分泌蛋白的 DEGs 包括小热休克蛋白和负延伸因子 B 样蛋白，它们协同作用以增加饲养于易感牛上的蜱的唾液腺中转录水平；26S 蛋白酶调节亚基 6B 和另一种与钙联蛋白相似的伴侣蛋白，也在饲养于易感牛上的蜱中上调；EF-手钙结合蛋白和丝氨酸羧肽酶 (SCP)，均参与血液凝固级联反应，并在饲养于易感牛上的蜱中上调；和两个核糖体蛋白，60S 酸性核糖体蛋白 P2 和 60S 核糖体蛋白 L19。这些结果有助于描述在易感和抗性宿主中牛蜱唾液腺基因表达，并提出了新的潜在控制目标蜱虫侵扰，因为那些参与血液喂养期间应激反应机制的基因。
