The rise and diversification of spidroins in the deep-time evolution of spiders

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  The rise and diversification of spidroins in the deep-time evolution of spiders Summary The evolutionary success of spiders is often attributed to their stunning ability to produce and utilize silk, but the potential link between the molecular and phenotypic basis of silk production and spider diversification is seldom tested in a robust dated phylogenetic framework. Here, we provide a macroevolutionary context for testing hypotheses by reconstructing and dating the spider tree of life using genomic and transcriptomic data. We searched exhaustively for members of the spider silk protein (spidroin) gene family from omics data and identified them in an iterative phylogenetic pipeline. Four distinct new types of spidroins with atypical sequence characteristics are discovered to be widespread in true spiders with the potential to affect silk properties, as inferred by our phylogenetic generalized linear mixed model and phylogenetic generalized least squares analyses. Combining our ro...

Acetylcholine-binding protein 5 regulates extracellular apoptosis in the wolf spider as a sacrificial ROS scavenger

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Acetylcholine-binding protein 5 regulates extracellular apoptosis in the wolf spider as a sacrificial ROS scavenger

Abstract

Apoptosis is regulated by a conserved gene network across species for maintaining homeostasis and stress response. While intracellular apoptotic pathways are well characterized, the extracellular mechanisms governing apoptosis remain largely unexplored, probably due to divergence in species-specific gene sets involved in extracellular regulation. Here, we uncover a novel extracellular apoptotic mechanism mediated by acetylcholine-binding protein 5 (AChBP5) in the wolf spider Pardosa pseudoannulata. AChBP5 is highly expressed in the spider fat-body (midgut diverticula), while other four AChBP genes are abundantly expressed in the tissue brain. Among five AChBP genes, only AChBP5 exhibited broad transcriptional induction upon exposure to various insecticides, including neonicotinoids and other classes. AChBP5 expression was also upregulated by reactive oxygen species (ROS) including H2O2, key triggers of apoptosis. Functional assays demonstrated that, in cultured cells, AChBP5 acted as an extracellular sacrifice buffer against oxidative stress to maintain cell viability, becoming progressively inactivated by ROS in a concentration-dependent manner. RNAi-mediated silencing of AChBP5 significantly increased spider susceptibility to both-induced and direct oxidative stress, underscoring its critical protective function. Collectively, these findings support a model in which lineage-specific genes, AChBP5 may contribute to extracellular modulation of apoptosis and provide a mechanism by which spiders could respond to chemical stressors.
Zhang, H., Wang, J., Tan, Y., Zhang, J., Shi, C., Hu, T., Wang, K., & Liu, Z. (2026). Acetylcholine-binding protein 5 regulates extracellular apoptosis in the wolf spider as a sacrificial ROS scavenger. Pesticide Biochemistry and Physiology, 219, 107001. https://doi.org/10.1016/j.pestbp.2026.107001