The arylsulfatase- and phospholipase-rich venom of the plutoniumid centipede Theatops posticus.

Research on centipede venoms has led to the discovery of a diverse array of novel proteins and peptides, including those with homology to previously discovered toxin families (e.g., phospholipase A2s and pM12a metalloproteases) and novel toxin families not previously detected in venoms (e.

Venom phenotype conservation suggests integrated specialization in a lizard-eating snake.

Biological specialization reduces the size of niche space while increasing efficiency in the use of available resources. Specialization often leads to phenotypic changes via natural selection aligning with niche space constraints. Commonly observed changes are in size, shape, behavior, and traits associated with feeding.

The remarkably enzyme-rich venom of the Big Bend Scorpion (Diplocentrus whitei).

Scorpion venoms have long been studied for their peptide discovery potential, with modern high-throughput venom-characterization techniques paving the way for the discovery of thousands of novel putative toxins. Research into these toxins has provided insight into the pathology and treatment of human diseases, even resulting in the development of one compound with Food and Drug Administration (FDA) approval. Although most of this research has focused on the toxins of scorpion species considered medically significant to humans, the venom of harmless scorpion species possess toxins that are homologous to those from medically significant species, indicating that harmless scorpion venoms may also serve as valuable sources of novel peptide variants.

De Novo Genome Assembly Highlights the Role of Lineage-Specific Gene Duplications in the Evolution of Venom in Fea's Viper (Azemiops feae).

Despite the medical significance to humans and important ecological roles filled by vipers, few high-quality genomic resources exist for these snakes outside of a few genera of pitvipers. Here we sequence, assemble, and annotate the genome of Fea's Viper (Azemiops feae). This taxon is distributed in East Asia and belongs to a monotypic subfamily, sister to the pitvipers.

Contrasting patterns of venom regeneration in a centipede (Scolopendra viridis) and a scorpion (Centruroides hentzi).

As biochemical traits with clear fitness consequences, venoms serve a critical ecological role for the animals that produce them. Understanding how venoms are maintained and regenerated after use will, therefore, provide valuable insight into the ecology of venomous animals. Furthermore, most studies on venomous organisms often require removing animals from the wild and waiting extended periods of time between venom extractions.

An integrative view of the toxic potential of Conophis lineatus (Dipsadidae: Xenodontinae), a medically relevant rear-fanged snake.

Most traditional research on snake venoms has focused on front-fanged snake families (Viperidae, Elapidae, and Atractaspididae). However, venom is now generally accepted as being a much more broadly possessed trait within snakes, including species traditionally considered harmless. Unfortunately, due to historical inertia and methodological challenges, the toxin repertoires of non-front-fanged snake families (e.

Phylogenetically diverse diets favor more complex venoms in North American pitvipers.

The role of natural selection in the evolution of trait complexity can be characterized by testing hypothesized links between complex forms and their functions across species. Predatory venoms are composed of multiple proteins that collectively function to incapacitate prey. Venom complexity fluctuates over evolutionary timescales, with apparent increases and decreases in complexity, and yet the causes of this variation are unclear.

The Tiger Rattlesnake genome reveals a complex genotype underlying a simple venom phenotype.

Variation in gene regulation is ubiquitous, yet identifying the mechanisms producing such variation, especially for complex traits, is challenging. Snake venoms provide a model system for studying the phenotypic impacts of regulatory variation in complex traits because of their genetic tractability. Here, we sequence the genome of the Tiger Rattlesnake, which possesses the simplest and most toxic venom of any rattlesnake species, to determine whether the simple venom phenotype is the result of a simple genotype through gene loss or a complex genotype mediated through regulatory mechanisms.

Sex-based venom variation in the eastern bark centipede (Hemiscolopendra marginata).

Sexually dimorphic traits are widespread across metazoans and are often the result of sex-specific inheritance or sex-based differences in gene expression. Intersexual differences have even been observed in invertebrate venoms, although the identification of these differences has been limited to the more well-studied groups, such as scorpions and spiders, where sex-based differences in morphology and behavior are apparent. Recent studies on centipede venom have identified evidence of intraspecific variation, but intersexual differences have not been reported.

Convergent recruitment of adamalysin-like metalloproteases in the venom of the red bark centipede (Scolopocryptops sexspinosus).

Many venom proteins have presumably been convergently recruited by taxa from diverse venomous lineages. These toxic proteins have characteristics that allow them to remain stable in solution and have a high propensity for toxic effects on prey and/or potential predators. Despite this well-established convergent toxin recruitment, some toxins seem to be lineage specific.

Female-biased population divergence in the venom of the Hentz striped scorpion (Centruroides hentzi).

Sex-biased genes are expressed at higher levels in one sex and contribute to phenotypic differences between males and females, as well as overall phenotypic variation within and among populations. Venom has evolved primarily for predation and defense, making venom expression a highly variable phenotype as a result of local adaptation. Several scorpion species have shown both intraspecific and intersexual venom variation, and males have been observed using venom in courtship and mating, suggesting the existence of venom-specific, sex-biased genes that may contribute to population divergence.

A global accounting of medically significant scorpions: Epidemiology, major toxins, and comparative resources in harmless counterparts.

Scorpions are an ancient and diverse venomous lineage, with over 2200 currently recognized species. Only a small fraction of scorpion species are considered harmful to humans, but the often life-threatening symptoms caused by a single sting are significant enough to recognize scorpionism as a global health problem. The continued discovery and classification of new species has led to a steady increase in the number of both harmful and harmless scorpion species.

Embryo-larval BDE-47 exposure causes decreased pathogen resistance in adult male fathead minnows (Pimephales promelas).

Exposures to polybrominated diphenyl ethers (PBDEs) have been shown to alter immune function in adult organisms across a variety of taxa. However, few if any studies have investigated the long-term consequences of early life stage PBDE exposures on immune function in fish. This study sought to determine the effects of early life stage BDE-47 exposure on pathogen resistance in the fathead minnow (Pimephales promelas) following an extended depuration period (≥180 d).

Early Life Stage Exposure to BDE-47 Causes Adverse Effects on Reproductive Success and Sexual Differentiation in Fathead Minnows (Pimephales promelas).

2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), a compound manufactured for use as a flame retardant, is a ubiquitous environmental contaminant and suspected endocrine disruptor. Though several studies have explored the reproductive effects of BDE-47 in adult fish, there is a paucity of data regarding the reproductive effects of early life stage exposure. The goal of this study was to assess the reproductive effects of early life stage BDE-47 exposure in fathead minnows (Pimephales promelas).