Wang Anni, Bolnick Daniel I
Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA.
Parasit Vectors. 2025 May 20;18(1):180. doi: 10.1186/s13071-025-06807-x.
Parasites secrete and excrete a variety of molecules that evolved to help establish and sustain infections within hosts. Parasite adaptation to their host may lead to between-population divergence in these excretory and secretory products (ESPs), but few studies have tested for intraspecific variation in helminth proteomes.
Schistocephalus solidus is a cestode that parasitizes the threespine stickleback, Gasterosteus aculeatus. We used an ultra-performance liquid chromatography-mass spectrometry protocol to characterize the ESPs and whole-body proteome of S. solidus. Specifically, we characterized the proteome of S. solidus at the plerocercoid stage from wild-caught stickleback from three lakes on Vancouver Island (British Columbia, Canada) and one lake in Alaska (USA). We tested for differences in proteome composition among the four populations and specifically between ESPs and body tissue.
Overall, we identified 1362 proteins in the total proteome of S. solidus, with 542 of the 1362 proteins detected exclusively in the ESPs. Of the ESP proteins, we found signaling peptides and transmembrane proteins that had not been previously detected or characterized in S. solidus. We also found that protein spectrum counts varied greatly among all lake populations.
These population-level differences were observed in both ESP and whole-body tissue types. Our study suggests that S. solidus can excrete and secrete a wide range of proteins which are distinct among populations. These differences might reflect plastic responses to host genotype differences, or evolved adaptations by Schistocephalus to different local host populations.
寄生虫分泌和排泄多种分子，这些分子在进化过程中有助于在宿主体内建立和维持感染。寄生虫对宿主的适应可能导致这些排泄和分泌产物（ESPs）在种群间出现差异，但很少有研究检测蠕虫蛋白质组的种内变异。
固着类吸虫是一种寄生于三刺鱼（学名：Gasterosteus aculeatus）的绦虫。我们使用超高效液相色谱-质谱分析法来表征固着类吸虫的ESPs和全身体蛋白质组。具体而言，我们对来自加拿大不列颠哥伦比亚省温哥华岛三个湖泊以及美国阿拉斯加一个湖泊的野生三刺鱼体内的成虫前期固着类吸虫的蛋白质组进行了表征。我们测试了这四个种群之间蛋白质组组成的差异，特别是ESPs和身体组织之间的差异。
总体而言，我们在固着类吸虫的总蛋白质组中鉴定出1362种蛋白质，其中1362种蛋白质中有542种仅在ESPs中检测到。在ESPs蛋白质中，我们发现了信号肽和跨膜蛋白，这些蛋白在固着类吸虫中以前未被检测到或表征过。我们还发现，所有湖泊种群的蛋白质谱计数差异很大。
在ESPs和全身组织类型中均观察到这些种群水平的差异。我们的研究表明，固着类吸虫可以排泄和分泌多种蛋白质，这些蛋白质在种群之间是不同的。这些差异可能反映了对宿主基因型差异的可塑性反应，或者是固着类吸虫对不同本地宿主种群的进化适应。
