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...

Pre-cheliceral region patterning in a spider provides new insights into the development and evolution of arthropod neurosecretory centres

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Pre-cheliceral region patterning in a spider provides new insights into the development and evolution of arthropod neurosecretory centres

Comparing head development among arthropods has helped identify ancestral aspects of brain patterning and structure in animals more generally. Most understanding of arthropod head patterning has been learned from insects and the myriapod Strigamia maritima. Chelicerates represent an outgroup to mandibulate arthropods and can provide a valuable perspective to arthropod evolution and development. We assayed the expression of key markers of head patterning and neurosecretory centres from mandibulates in the pre-cheliceral region of embryos of the spider Parasteatoda tepidariorum. We found that, like mandibulates, this spider likely has a pars intercerebralis, marked by six3.2 and visual system homeobox/chx. We also found some evidence for another neurosecretory centre, the pars lateralis, marked by six3.2 and fasciclin 2. Furthermore, we identified anterior-medial cells in the spider pre-cheliceral region that express six3.2, foxQ2 and collier1, suggesting they may be pioneer neurons. However, these spider cells do not appear to be equivalent to the central pioneer neuronal cells identified in S. maritima because they lack expression of other key markers. Taken together, our study of spider pre-cheliceral region patterning adds a new chelicerate perspective to understanding the development and evolution of the arthropod head.

Amber Harper, Lauren Sumner-Rooney, Ralf Janssen, Alistair P. McGregor; Pre-cheliceral region patterning in a spider provides new insights into the development and evolution of arthropod neurosecretory centres. Open Biol 1 April 2026; 16 (4): 250428. https://doi.org/10.1098/rsob.250428