Alcaide, MariaMoutinho Cabral, InêsCarvalho, LaraMendes, Vera M.Alves de Matos, António P.Manadas, BrunoSaúde, LeonorD’Ambrosio, MariaelenaCosta, Pedro M.2024-04-172024-04-172024-03-212076-2615PURE: 87469604PURE UUID: 50e32ecf-6901-497b-a7d1-edd0714725a8Scopus: 85188816379WOS: 001191879000001PubMed: 38540078PubMedCentral: PMC10967595http://hdl.handle.net/10362/166304Fundo Azul co-financed project MARVEN (FA_05_2017_007). The Portuguese Foundation for Science and Technology (FCT), i.p., is acknowledged for funding the projects UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences-UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy-i4HB; UIDB/04539/2020, UIDP/04539/2020 and LA/P/0058/2020, and the National Mass Spectrometry Network (RNEM) [POCI-01-0145-FEDER-402-022125 Ref. ROTEIRO/0028/2013). IMC also acknowledges FCT for the Ph.D. grant ref. 2022.11150.BD.The current study investigates the venom-delivery system of green and red morphotypes of the sea anemone Actinia equina to disclose its potential as a source of bioactive compounds. We compared the two morphotypes using electron and optical microscopy, proteomics, and toxicity assessment on zebrafish embryos. Specialized venom-injecting cells (nematocysts) are equally distributed and found in the tentacles of both varieties. Proteomics revealed proteins of interest in both red and green Actinia, yielding the three most abundant Gene Ontology (GO) terms related to the biological processes “proteolysis”, “hemolysis in another organism” and “lipid catabolic process”. Neurotoxins and cytolytic toxins similar to known cnidarian toxins like PsTX-60A and AvTX-60A, for instance, were identified in both types. Extracts from green and red anemones were toxic to zebrafish embryos, with green anemone venom appearing to be more potent. The findings highlight the presence of proteinaceous toxins in A. equina and the potential for different varieties to possess distinct bioactive compounds. Notably, pore-forming toxins are suggested for molecular probes and immunotoxins, making them valuable assets for potential biotechnological and biomedical purposes.176897444engbioinformaticscnidariaelectron microscopyhistologymarine bioprospectingproteomicstoxicitytoxinsAnimal Science and ZoologyGeneral VeterinarySDG 14 - Life Below Waterjournal article10.3390/ani14060981https://www.scopus.com/pages/publications/85188816379