%ASantibáñez-López, Carlos [Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA]%AKriebel, Ricardo [Department of Botany, University of Wisconsin-Madison, Madison, WI, USA]%ABallesteros, Jesús [Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA]%ARush, Nathaniel [Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA]%AWitter, Zachary [Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA]%AWilliams, John [Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA]%AJanies, Daniel [Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA]%ASharma, Prashant [Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA]%BJournal Name: PeerJ; Journal Volume: 6; Related Information: CHORUS Timestamp: 2019-11-01 22:57:47 %D2018%IPeerJ %JJournal Name: PeerJ; Journal Volume: 6; Related Information: CHORUS Timestamp: 2019-11-01 22:57:47 %K %MOSTI ID: 10079507 %PMedium: X %TIntegration of phylogenomics and molecular modeling reveals lineage-specific diversification of toxins in scorpions %X

Scorpions have evolved a variety of toxins with a plethora of biological targets, but characterizing their evolution has been limited by the lack of a comprehensive phylogenetic hypothesis of scorpion relationships grounded in modern, genome-scale datasets. Disagreements over scorpion higher-level systematics have also incurred challenges to previous interpretations of venom families as ancestral or derived. To redress these gaps, we assessed the phylogenomic relationships of scorpions using the most comprehensive taxonomic sampling to date. We surveyed genomic resources for the incidence of calcins (a type of calcium channel toxin), which were previously known only from 16 scorpion species. Here, we show that calcins are diverse, but phylogenetically restricted only to parvorder Iurida, one of the two basal branches of scorpions. The other branch of scorpions, Buthida, bear the related LKTx toxins (absent in Iurida), but lack calcins entirely. Analysis of sequences and molecular models demonstrates remarkable phylogenetic inertia within both calcins and LKTx genes. These results provide the first synapomorphies (shared derived traits) for the recently redefined clades Buthida and Iurida, constituting the only known case of such traits defined from the morphology of molecules.

%0Journal Article