Wishbone spider venom gland transcriptomes
Aname is among the most abundant and diverse mygalomorph spider genera, having colonised most of the Australian continent. So far, toxinological research has neglected this genus with an estimated fauna of 200 to 300 species, which remains to be explored for bioactive molecules of interest for potential insecticidal or biotechnological applications. We investigated the venom of three Aname species (Aname villosa, Aname ferruginea, and Aname ssp, the former is an uncharacterized species) collected in Queensland, Australia using a combined approach of venom gland transcriptomics and proteomics, and pharmacological investigations of their venoms and components using high throughput fluorescence calcium influx assays and insecticidal assays in Drosophila melanogaster and Periplaneta americana. We found Aname produces low complexity venoms but with interesting unique toxin characterized by novel cysteine-rich scaffold motifs in all three species. Not surprisingly, most of the toxins were within the highly conserved inhibitor cystine knot motif that is predominant among spider venom toxins. Venoms and toxins pharmacology revealed a significant enhancement of ion channel activation, in particularly on the L-type calcium channel. Two venom peptides derived from A. ferruginea were selected for further investigations, Af1a and Af12a, with their synthetic forms showing high selectivity for potentiation of mammalian L-type over N-type calcium channels, and no activity on voltage-gated sodium channels. In vivo activity tests in Drosophila showed these peptides have potent insecticidal activity, particularly Af1a. Such selective pharmacological profile highlights these venom peptides as unique bioactive molecules with potential applications in the development of pharmacological agents and bioinsecticides. Altogether, our study is the first report on the composition and pharmacology of Aname venoms and contributes to unravelling the fascinating molecular and pharmacological repertoire of the Australian mygalomorph spider fauna.