Transcriptomic Insights Into the Evolution of Snake Venom: Mechanisms, Diversity, and Adaptation

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  Transcriptomic Insights Into the Evolution of Snake Venom: Mechanisms, Diversity, and Adaptation Abstract Snake venoms are evolutionarily refined biochemical arsenals composed of diverse toxins with complex functional roles in predation, defense, and competition. Over the past 2 decades, transcriptomic approaches have transformed venom research by enabling high-resolution insights into gene expression dynamics, molecular diversity, and the evolutionary mechanisms driving venom variation across lineages. In this review, we present a comprehensive synthesis of snake venom transcriptomics literature and propose a conceptual framework structured around three major axes: (1) gene family expansion through duplication and neofunctionalization; (2) regulatory complexity encompassing transcriptional, posttranscriptional, and epigenetic modulation; and (3) ecological selection pressures shaping venom profiles in response to diet, habitat, and interspecific interactions. We integrate findin...

Sensory Enrichment and Deprivation During Development: Limited Effects on the Volumes of CNS Neuropils in Two Spiders With Different Ecology

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Sensory Enrichment and Deprivation During Development: Limited Effects on the Volumes of CNS Neuropils in Two Spiders With Different Ecology

ABSTRACT

Neuroplasticity is a core property of animal nervous systems, enabling structural changes in the brain in response to environmental stimuli or internal processes such as learning. Among spiders—a diverse group of predators—neuroanatomy varies with hunting strategy: stationary species that build capture webs differ from cursorial species that hunt without webs, reflecting reliance on distinct sensory modalities. While neuroplasticity has been documented in cursorial jumping spiders, its direct drivers remain unclear. In this study, we tested how sensory input influences the central nervous system (CNS) and whether stationary and cursorial hunters differ in their plastic responses. Using sensory deprivation and enrichment, we reared spiders under four treatments: control (CON), vibratory enrichment (VIB), visual enrichment (VIS), and combined enrichment (VISVIB). We examined the stationary hunter Parasteatoda tepidariorum and the cursorial hunter Marpissa muscosa. We predicted that enrichment would enlarge neuropil volumes in modality-specific brain regions, with stronger vibratory effects in P. tepidariorum and stronger visual effects in M. muscosa. Contrary to our expectations, sensory enrichment did not increase the volume of the corresponding CNS neuropils in either species. Although certain neuropils showed significant differences in specific groups, no clear causal link to sensory input emerged. Instead, a substantial proportion of the variation in neuropil volume was explained by family effects (shared maternal origin). We discuss these findings in the context of potential mechanisms underlying environmental plasticity in the spider brain.

M. Steinhoff, P. O., Mouginot, P., & Uhl, G. B. (2025). Sensory Enrichment and Deprivation During Development: Limited Effects on the Volumes of CNS Neuropils in Two Spiders With Different Ecology. Journal of Comparative Neurology, 533(11), e70102. https://doi.org/10.1002/cne.70102