In silico characterization of the neuropeptidome of the Western black widow spider Latrodectus hesperus

•The first peptidome for a member of the Araneae (true spiders) was deduced.•Latrodectus hesperus transcripts encoding 23 peptide families were identified.•The structures of 216 mature peptides were predicted, most of which are novel.•Atypical, FLP, NPF, sulfakinin, orcokinin and TRP family members are described.•These data provide a new resource for studying peptidergic control in the Araneae.

Technological advancements in high-throughput sequencing have resulted in the production/public deposition of an ever-growing number of arthropod transcriptomes. While most sequencing projects have focused on hexapods, transcriptomes have also been generated for members of the Chelicerata. One chelicerate for which a large transcriptome has recently been released is the Western black widow Latrodectus hesperus, a member of the Araneae (true spiders). Here, a neuropeptidome for L. hesperus was predicted using this resource. Thirty-eight peptide-encoding transcripts were mined from the L. hesperus transcriptome, with 216 distinct peptides predicted from the deduced pre/preprohormones. The identified peptides included members of the allatostatin A, allatostatin B, allatostatin C, allatotropin, bursicon α, bursicon β, CAPA/periviscerokinin/pyrokinin, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/ion transport peptide, diuretic hormone 31, diuretic hormone 44, FMRFamide-like peptide (FLP), GSEFLamide, insulin-like peptide, neuropeptide F (NPF), orcokinin, proctolin, short neuropeptide F, SIFamide, sulfakinin and tachykinin-related peptide (TRP) families. Of particular note were the identifications of a carboxyl (C)-terminally extended corazonin, FLPs possessing –IMRFamide, –MMYFamide, and –MIHFamide C-termini, a NPF and a sulfakinin each ending in –RYamide rather than –RFamide, a precursor whose orcokinins include C-terminally amidated isoforms, and a collection of TRPs possessing –FXPXLamide rather than the stereotypical –FXGXLamide C-termini. The L. hesperus peptidome is by far the largest thus far published for any member of the Chelicerata. Taken collectively, these data serve as a reference for future neuropeptide discovery in the Araneae and provide a foundation for future studies of peptidergic control in L. hesperus and other spiders.