Table_1_Gene Expression in the Salivary Gland of Rhipicephalus (Boophilus) microplus Fed on Tick-Susceptible and Tick-Resistant Hosts.XLS

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 Bos indicus cattle. To identify candidates for the development of novel control strategies for the cattle tick Rhipicephalus (Boophilus) microplus, a salivary gland transcriptome analysis of engorged females fed on susceptible or resistant hosts was performed. Using RNA-Seq, transcriptomes were de novo 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 HSP 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 (SCP), 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.

牛蜱成功附着主要依赖于其分泌的能够改变宿主免疫反应的物质。其中大部分物质由寄生虫唾液腺表达并通过蜱唾液分泌。已知宿主能够对蜱虫和欧洲牛种产生免疫反应，而工业杂交牛对蜱虫的侵袭更为敏感。为了鉴定开发针对牛蜱（Rhipicephalus (Boophilus) microplus）新型控制策略的候选基因，对以易感或抗性宿主为食的饱血雌蜱的唾液腺转录组进行了分析。利用RNA-Seq技术，对转录组进行了从头组装，共产生235,451个连续序列，转录组完整性达到93.3%。差异表达分析识别出137个序列为在易感牛和抗性牛饲养的蜱虫中差异表达的基因（DEGs）。预测为分泌蛋白的DEGs包括间隙连接蛋白（innexins），其为形成间隙连接通道的跨膜蛋白；Na+/二羧酸盐、Na+/三羧酸盐和磷酸转运蛋白以及一个假定的单羧酸盐转运蛋白；一个磷脂酰肌醇4-磷酸结合蛋白；一个富含半胱氨酸的蛋白，含有类似于胰蛋白酶抑制剂的（TIL）结构域；一个含有滑车蛋白结构域的假定的防御蛋白3；以及一个具有CARMIL_C结构域的F-肌动蛋白去帽蛋白LRRC16A；这些基因在以易感牛为食的蜱虫中上调。预测为非分泌蛋白的DEGs包括一个小热休克蛋白和负性延长因子B样蛋白，两者协同作用以增加以易感牛为食的蜱虫唾液腺中HSP转录水平；26S蛋白酶调节亚基6B和另一个与钙网蛋白相似的伴侣蛋白，也在以易感牛为食的蜱虫中上调；一个EF手钙结合蛋白和一个丝氨酸羧肽酶（SCP），两者均参与血液凝固级联反应并在以易感牛为食的蜱虫中上调；以及两个核糖体蛋白，60S酸性核糖体蛋白P2和60S核糖体蛋白L19。这些结果有助于表征牛蜱在易感牛和抗性牛宿主中的唾液腺基因表达，并提出了新的潜在靶点，以控制蜱虫的侵袭，因为这些基因参与了吸血过程中的压力反应机制。