Transcriptome Analysis of Scorpion Species Belonging to the Vaejovis Genus

Abstract

Scorpions belonging to the Buthidae family have traditionally drawn much of the biochemist’s attention due to the strong toxicity of their venoms. Scorpions not toxic to mammals, however, also have complex venoms. They have been shown to be an important source of bioactive peptides, some of them identified as potential drug candidates for the treatment of several emerging diseases and conditions. It is therefore important to characterize the large diversity of components found in the non-Buthidae venoms. As a contribution to this goal, this manuscript reports the construction and characterization of cDNA libraries from four scorpion species belonging to the Vaejovis genus of the Vaejovidae family: Vaejovis mexicanus, V. intrepidus, V. subcristatus and V. punctatus. Some sequences coding for channel-acting toxins were found, as expected, but the main transcribed genes in the glands actively producing venom were those coding for non disulfide-bridged peptides. The ESTs coding for putative channel-acting toxins, corresponded to sodium channel β toxins, to members of the potassium channel-acting α or κ families, and to calcium channel-acting toxins of the calcin family. Transcripts for scorpine-like peptides of two different lengths were found, with some of the species coding for the two kinds. One sequence coding for La1-like peptides, of yet unknown function, was found for each species. Finally, the most abundant transcripts corresponded to peptides belonging to the long chain multifunctional NDBP-2 family and to the short antimicrobials of the NDBP-4 family. This apparent venom composition is in correspondence with the data obtained to date for other non-Buthidae species. Our study constitutes the first approach to the characterization of the venom gland transcriptome for scorpion species belonging to the Vaejovidae family.

Venom Gland Transcriptomic and Proteomic Analyses of the Enigmatic Scorpion Superstitionia donensis (Scorpiones: Superstitioniidae), with Insights on the Evolution of Its Venom Components

“…Following the scheme presented in recent venom gland transcriptome analyses [6,11], we report here 135 sequences putatively coding for the following known venom peptides and proteins (Figure 2):…”

“…Calcins, toxins affecting calcium channels, are structurally characterized by an inhibitor cystine knot (ICK) motif, making them different from the sodium, chloride and potassium channel toxins [10,11,12]. They were first discovered in the venom of the buthid scorpions: Hottentotta hottentotta (= Buthotus hottentotta ) in 1991 [13]; Hottentotta judaicus (= Buthotus judaicus ) in 1996 [14]; and Mesobuthus martensii in 1997 [15].…”

“…La1-like, long-chain peptides with eight cysteines [11], are also ubiquitous in scorpion venoms. They have been described in the venom of species belonging to 10 out of the 11 families studied so far (Table 2); and interestingly their function remains unknown.…”

Scorpion toxin peptide action at the ion channel subunit level

“…The physiological effects of scorpion envenomation, such as modulation of central and peripheral nervous system excitability, altered smooth and skeletal muscle activity, and membrane destabilisation, are primarily mediated through the action of small neuropeptides on various ion channels in excitable membranes, a process thought to have developed in response to extended positive selection pressure via predator-prey interactions (M enez et al, 1992;Goudet et al, 2002;Tytgat et al, 1999). These peptides can be characterised generically (disulfide bridge-containing peptides and non-disulfide bridge-containing peptides) (Zeng et al, 2005), or by the size of the peptide chain (short chain peptides, usually potassium channel blockers, or long-chain peptides, usually sodium channel modulators) (Quintero-Hernandez et al, 2015;Santibanez-Lopez and Possani, 2015).…”

Improved System for Constructing Bacterial cDNA Libraries From the Venom Glands of Two Iranian Scorpions

“…After, the cells grow in agar media. Finally, in isolating every clone in the library, the primary aim outlined above is obtained (5)(6)(7)(8).…”