Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic.
Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic.
PLoS One. 2020 Mar 24;15(3):e0230537. doi: 10.1371/journal.pone.0230537. eCollection 2020.
During the blood feeding, sand fly females inject saliva containing immunomodulatory and anti-haemostatic molecules into their vertebrate hosts. The saliva composition is species-specific, likely due to an adaptation to particular haemostatic pathways of their preferred host. Research on sand fly saliva is limited to the representatives of two best-studied genera, Phlebotomus and Lutzomyia. Although the members of the genus Sergentomyia are highly abundant in many areas in the Old World, their role in human disease transmission remains uncertain. Most Sergentomyia spp. preferentially attack various species of reptiles, but feeding on warm-blooded vertebrates, including humans and domestic animals, has been repeatedly described, especially for Sergentomyia schwetzi, of which salivary gland transcriptome and proteome is analyzed in the current study. Illumina RNA sequencing and de novo assembly of the reads and their annotation revealed 17,293 sequences homologous to other arthropods' proteins. In the sialome, all proteins typical for sand fly saliva were identified-antigen 5-related, lufaxin, yellow-related, PpSP15-like, D7-related, ParSP25-like, and silk proteins, as well as less frequent salivary proteins included 71kDa-like, ParSP80-like, SP16-like, and ParSP17-like proteins. Salivary enzymes include apyrase, hyaluronidase, endonuclease, amylase, lipase A2, adenosine deaminase, pyrophosphatase, 5'nucleotidase, and ribonuclease. Proteomics analysis of salivary glands identified 631 proteins, 81 of which are likely secreted into the saliva. We also compared two S. schwetzi lineages derived from the same origin. These lineages were adapted for over 40 generations for blood feeding either on mice (S-M) or geckos (S-G), two vertebrate hosts with different haemostatic mechanisms. Altogether, 20 and 40 annotated salivary transcripts were up-regulated in the S-M and S-G lineage, respectively. Proteomic comparison revealed ten salivary proteins more abundant in the lineage S-M, whereas 66 salivary proteins were enriched in the lineage S-G. No difference between lineages was found for apyrase activity; contrarily the hyaluronidase activity was significantly higher in the lineage feeding on mice.
在吸血过程中，沙蝇雌性将含有免疫调节和抗凝血分子的唾液注入其脊椎动物宿主。唾液成分具有物种特异性，这可能是由于适应了其首选宿主的特定止血途径。沙蝇唾液的研究仅限于两个研究最充分的属，即白蛉属和卢特佐米亚属的代表。尽管旧世界许多地区的属 Sergentomyia 成员非常丰富，但它们在人类疾病传播中的作用仍不确定。大多数 Sergentomyia spp. 更喜欢攻击各种爬行动物，但也有报道称它们会吸食温血脊椎动物，包括人类和家畜，尤其是 Sergentomyia schwetzi，目前对其唾液腺转录组和蛋白质组进行了分析。Illumina RNA 测序和reads 的从头组装及其注释揭示了 17293 个与其他节肢动物蛋白同源的序列。在唾液组中，鉴定出了所有与沙蝇唾液相关的典型蛋白——抗原 5 相关蛋白、lufaxin、黄色相关蛋白、PpSP15 样蛋白、D7 相关蛋白、ParSP25 样蛋白和丝蛋白，以及较少见的唾液蛋白，包括 71kDa 样蛋白、ParSP80 样蛋白、SP16 样蛋白和 ParSP17 样蛋白。唾液酶包括脱氨酶、透明质酸酶、内切核酸酶、淀粉酶、脂肪酶 A2、腺苷脱氨酶、焦磷酸酶、5'nucleotidase 和核糖核酸酶。唾液腺蛋白质组学分析鉴定出 631 种蛋白质，其中 81 种可能分泌到唾液中。我们还比较了来自同一来源的两个 S. schwetzi 谱系。这两个谱系在 40 多代的进化过程中适应了两种不同止血机制的脊椎动物宿主，即老鼠（S-M）或壁虎（S-G）。分别在 S-M 和 S-G 谱系中上调了 20 和 40 个注释的唾液转录本。蛋白质组比较发现，在 S-M 谱系中 10 种唾液蛋白更为丰富，而在 S-G 谱系中 66 种唾液蛋白更为丰富。在谱系中没有发现脱氨酶活性的差异；相反，在以老鼠为食的谱系中，透明质酸酶活性显著升高。
