Molecular Diversity and Gene Evolution of the Venom Arsenal of Terebridae Predatory Marine Snails.
Bottom Line: Phylogenetic methodology was used to identify 14 teretoxin gene superfamilies for the first time, 13 of which are unique to the Terebridae.Additionally, basic local algorithm search tool homology-based searches to venom-related genes and posttranslational modification enzymes identified a convergence of certain venom proteins, such as actinoporin, commonly found in venoms.This research provides novel insights into venom evolution and recruitment in Conoidean predatory marine snails and identifies a plethora of terebrid venom peptides that can be used to investigate fundamental questions pertaining to gene evolution.
Affiliation: Hunter College and The Graduate Center, City University of New York Invertebrate Zoology, Sackler Institute for Comparative Genomics, American Museum of Natural History, New York.Show MeSH
Mentions: Two terebrid species, Triplostephanus anilis (Röding, 1798) and Terebra subulata (Linnaeus, 1767), were selected for venom duct transcriptome characterization using NGS (fig. 2). Both species belong to a lineage of venomous terebrids that has been identified as clade C in a recent phylogenetic reconstruction of the Terebridae (Castelin et al. 2012). Terebrids are vermivorous (worm hunting) and certain lineages, similar to cone snails, use a sophisticated venom apparatus to inject a cocktail of peptide toxins to rapidly immobilize their prey. The conoidean venom apparatus includes a convoluted tubular venom gland with a muscular bulb, propulsing the venomous secretion. Conoidea have evolved a peculiar mechanism of using marginal radular teeth for stabbing the prey, and in some groups the latter are modified in hypodermic needles to inject venom into the prey (Taylor et al. 1993; Kantor and Taylor 2000; Holford, Puillandre, Modica, et al. 2009; Holford, Puillandre, Terryn, et al. 2009; Castelin et al. 2012). Not all terebrids have a venom apparatus, and at least three different hunting physiologies are described for this family (Miller 1970). Recent studies have facilitated the identification of terebrid lineages that produce venom by correlating the molecular phylogeny of the Terebridae to the evolution of its venom apparatus (Holford, Puillandre, Modica, et al. 2009; Holford, Puillandre, Terryn, et al. 2009; Castelin et al. 2012). Using this biodiversity derived discovery approach, Tr. anilis and Te. subulata were selected for venom characterization, as they are representatives of a clade that has a similar venom apparatus to that of cone snails and produce venom peptides to subdue their prey.Fig. 2.—
Affiliation: Hunter College and The Graduate Center, City University of New York Invertebrate Zoology, Sackler Institute for Comparative Genomics, American Museum of Natural History, New York.