Venomous Noodles: The Evolution of Toxins in Nemertea through Positive Selection and Gene Duplication
Author:
Sonoda Gabriel Gonzalez12, Tobaruela Eric de Castro3ORCID, Norenburg Jon4ORCID, Fabi João Paulo3ORCID, Andrade Sónia C. S.1ORCID
Affiliation:
1. Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo 05508-090, Brazil 2. Instituto Butantan, São Paulo 05503-900, Brazil 3. Faculdade de Ciências Farmacêuticas, Food Research Center (FoRC), Universidade de São Paulo, São Paulo 05508-080, Brazil 4. Smithsonian Institution, Washington, DC 20024, USA
Abstract
Some, probably most and perhaps all, members of the phylum Nemertea are poisonous, documented so far from marine and benthic specimens. Although the toxicity of these animals has been long known, systematic studies on the characterization of toxins, mechanisms of toxicity, and toxin evolution for this group are scarce. Here, we present the first investigation of the molecular evolution of toxins in Nemertea. Using a proteo-transcriptomic approach, we described toxins in the body and poisonous mucus of the pilidiophoran Lineus sanguineus and the hoplonemertean Nemertopsis pamelaroeae. Using these new and publicly available transcriptomes, we investigated the molecular evolution of six selected toxin gene families. In addition, we also characterized in silico the toxin genes found in the interstitial hoplonemertean, Ototyphlonemertes erneba, a meiofaunal taxa. We successfully identified over 200 toxin transcripts in each of these species. Evidence of positive selection and gene duplication was observed in all investigated toxin genes. We hypothesized that the increased rates of gene duplications observed for Pilidiophora could be involved with the expansion of toxin genes. Studies concerning the natural history of Nemertea are still needed to understand the evolution of their toxins. Nevertheless, our results show evolutionary mechanisms similar to other venomous groups.
Subject
Health, Toxicology and Mutagenesis,Toxicology
Reference149 articles.
1. Norenburg, J., Gibson, R., Herrera Bachiller, A., and Strand, M. (2023, July 30). World Nemertea Database. Available online: https://www.Marinespecies.Org/Nemertea. 2. Brusca, R.C., Moore, W., and Shuster, S.M. (2016). Invertebrates, Sinauer Associates, Inc.. [3rd ed.]. 3. Nemertean Taxonomy Implementing Changes in the Higher Ranks, Dismissing Anopla and Enopla;Strand;Zool. Scr.,2019 4. A Transcriptomic Approach to Ribbon Worm Systematics (Nemertea): Resolving the Pilidiophora Problem;Andrade;Mol. Biol. Evol.,2014 5. Göransson, U., Jacobsson, E., Strand, M., and Andersson, H.S. (2019). The Toxins of Nemertean Worms. Toxins, 11.
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