Venom collection and analysis in the pseudoscorpion Chelifer cancroides (Pseudoscorpiones: Cheliferidae). (15th April 2019)

• Record Type: Journal Article
• Authors: Krämer, Jonas; Pohl, Hans; Predel, Reinhard
• Is Part Of: Toxicon. Volume 162(2019)
• Page Start: 15
• Page End: 23
• Publication Date: 2019-04-15
• Subjects: Pseudoscorpion -- Chelifer cancroides -- Lamina defensor -- Venom collection -- Transcriptome -- Mass spectrometry fingerprints -- Antimicrobial peptides; Toxins -- Periodicals; Venom -- Periodicals; 615.9
• DOI: 10.1016/j.toxicon.2019.02.009
• Languages: English
• ISSNs: 0041-0101

Abstract

Abstract: Pseudoscorpions are very small arthropods with almost worldwide distribution. They possess a unique venom delivery system in the chelal hands of their pedipalps that has evolved independently from that of scorpions and spiders. Studies on the venom composition of pseudoscorpions are very rare. Recently, the potential venom composition of the pseudoscorpion Synsphyronus apimelus Harvey, 1987 (Pseudoscorpiones: Garypidae) has been studied by transcriptome analysis. However, a proteome analysis of venom to identify the genuine venom compounds of pseudoscorpions has not yet been performed. In our study, we have developed a non-invasive approach for extracting minute amounts of venom, which for the first time allowed collecting pure venom samples of pseudoscorpions with minimal contaminations and high reproducibility. These experiments first required a morphological investigation of the venom delivery system with a focus on the role of the lamina defensor in the release of venom. Likely, the venom delivery system of pseudoscorpions has a mechanism that prevents the release of venom if the prey is not successfully penetrated by a venom tooth. Electrical stimulation of a gland-containing chelal hand in combination with a mechanical stimulation of the lamina defensor at the base of the venom tooth resulted in an average of 5 nl of collected venom. The utility of the method was then validated by repeated venom extractions and subsequent analysis of the venom composition using MALDI-TOF mass fingerprinting. Subsequent proteomics analysis in combination with transcriptome analyses of chelal hand tissue has identified the first genuine venom compounds of pseudoscorpions with putative antimicrobial peptides. For our experiments, we used the house pseudoscorpion Chelifer cancroides (Linnaeus, 1758) (Pseudoscorpiones: Cheliferidae). Highlights: First protocol for extraction and analysis of the venom of pseudoscorpions. Venom extraction required both mechanical and electrical stimuli. Combined peptidomic and transcriptomic analyses revealed sequences of several venom components. Experimentally determined precursors show sequence similarity with antimicrobial peptides of scorpions.