Tracking the recruitment and evolution of snake toxins using the evolutionary context provided by the <i>Bothrops jararaca</i> genome
Diego Dantas Almeida, Vincent Louis Viala, Pedro G. Nachtigall, Michael Broe, H. Lisle Gibbs, Solange M.T. Serrano, Ana M. Moura‐da‐Silva, Paulo Lee Ho, Milton Yutaka Nishiyama, Inácio L.M. Junqueira-de-Azevedo
Abstract
(PLA2) have expanded in genomic proximity to their nonvenomous ancestors; 2) serine proteinases arose by co-opting a local gene that also gave rise to lizard gilatoxins and then expanded; 3) the bradykinin-potentiating peptides originated from a C-type natriuretic peptide gene backbone; and 4) VEGF-F was co-opted from a PGF-like gene and not from VEGF-A. We evaluated two scenarios for the original recruitment of nontoxin genes for snake venom: 1) in locus ancestral gene duplication and 2) in locus ancestral gene direct co-option. The first explains the origins of two important toxins (SVMP and PLA2), while the second explains the emergence of a greater number of venom components. Overall, our results support the idea of a locally assembled venom arsenal in which the most clinically relevant toxin families expanded through posterior gene duplications, regardless of whether they originated by duplication or gene co-option.