Solenodon genome reveals convergent evolution of venom in eulipotyphlan mammals
AuthorsCasewell, Nicholas R.
Karlsson, Elinor K.
Card, Daren C.
Mychajliw, Alexis M.
Ngum, Neville M.
Kennerley, Rosalind J.
Brocca, Jorge L.
UMass Chan AffiliationsProgram in Bioinformatics and Integrative Biology
KeywordsConvergent molecular evolution
Biochemistry, Biophysics, and Structural Biology
Ecology and Evolutionary Biology
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AbstractVenom systems are key adaptations that have evolved throughout the tree of life and typically facilitate predation or defense. Despite venoms being model systems for studying a variety of evolutionary and physiological processes, many taxonomic groups remain understudied, including venomous mammals. Within the order Eulipotyphla, multiple shrew species and solenodons have oral venom systems. Despite morphological variation of their delivery systems, it remains unclear whether venom represents the ancestral state in this group or is the result of multiple independent origins. We investigated the origin and evolution of venom in eulipotyphlans by characterizing the venom system of the endangered Hispaniolan solenodon (Solenodon paradoxus). We constructed a genome to underpin proteomic identifications of solenodon venom toxins, before undertaking evolutionary analyses of those constituents, and functional assessments of the secreted venom. Our findings show that solenodon venom consists of multiple paralogous kallikrein 1 (KLK1) serine proteases, which cause hypotensive effects in vivo, and seem likely to have evolved to facilitate vertebrate prey capture. Comparative analyses provide convincing evidence that the oral venom systems of solenodons and shrews have evolved convergently, with the 4 independent origins of venom in eulipotyphlans outnumbering all other venom origins in mammals. We find that KLK1s have been independently coopted into the venom of shrews and solenodons following their divergence during the late Cretaceous, suggesting that evolutionary constraints may be acting on these genes. Consequently, our findings represent a striking example of convergent molecular evolution and demonstrate that distinct structural backgrounds can yield equivalent functions.
Proc Natl Acad Sci U S A. 2019 Dec 17;116(51):25745-25755. doi: 10.1073/pnas.1906117116. Epub 2019 Nov 26. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/25869
Full list of authors omitted for brevity. For full list see article.
RightsCopyright © 2019 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY).
Except where otherwise noted, this item's license is described as Copyright © 2019 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY).