Integrated venom-gland transcriptomic and venom proteomic analysis of the spider Vacrothele uncata reveals the toxin diversity.

Abstract

Venom is a complex bioactive mixture that evolved across diverse animal lineages for both predation and defense. While spiders are iconic venomous animals with immense species diversity, the molecular composition and pharmacological mechanisms of most spider venoms remain poorly understood. Vacrothele uncata (Macrothelidae) is an important agricultural predator widely distributed in the Simao District of Yunnan Province, China. Despite its ecological significance, systematic research into its venom components has been lacking. In this study, we performed the first systematic analysis of the molecular diversity of V. uncata venom by integrating venom gland transcriptomics with proteomics. At the transcriptomic level, 97 putative toxin-encoding transcripts were identified, including 17 canonical disulfide-rich peptide neurotoxins (DRPs). Based on their cysteine scaffold patterns, these DRPs were classified into 10 distinct superfamilies. Additionally, the transcriptome revealed other venom components, such as cysteine-rich secretory proteins (CRISPs) and tachylectin-like proteins. At the proteomic level, 84 proteins were detected in the venom proteome, of which 18 showed direct correspondence to transcripts identified in the venom gland transcriptome. These proteins were categorized into three groups: DRPs (n = 7), enzymatic and non-enzymatic proteins (n = 11), and uncharacterized toxins (n = 66), confirming toxin expression at the translational level. This study not only characterizes the molecular makeup of V. uncata venom but also provides essential data for understanding the predatory and defensive biology of this species, establishing a foundation for the discovery of novel pharmaceutical leads and bio-insecticide candidates.