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...

Biogeography of the widespread Aotearoa New Zealand mite harvester genus Rakaia (Arachnida, Opiliones, Cyphophthalmi) based on UCE-derived subgenomic data

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Biogeography of the widespread Aotearoa New Zealand mite harvester genus Rakaia (Arachnida, Opiliones, Cyphophthalmi) based on UCE-derived subgenomic data

Abstract

Aotearoa New Zealand is home to a remarkable number of endemic taxa, some of which have existed on the archipelago since before the breakup of Gondwana. The mite harvesters (suborder Cyphophthalmi), tiny non-spider arachnids that dwell in forest leaf litter and caves, are one such group. The mite harvester family Pettalidae Shear exhibits a classic Gondwanan distribution with notable diversity in Aotearoa, which is home to three pettalid genera. Our research focuses on the evolution of the most widespread and speciose Aotearoa pettalid genus, Rakaia Hirst, 1926. Through phylogenetic analysis, we provide a window into patterns of ancient diversification and infer historical biogeographic trends. We generated subgenomic data through target enrichment of ultraconserved elements (UCEs) using an Arachnida-specific probe set; the 50% and 75% taxon-occupancy matrix retrieved 848 and 585 loci, respectively. In addition to generating the first fully resolved phylogeny of Rakaia, we performed a molecular clock analysis and tested for shifts in diversification rates in order to explore the effect of geological events such as the Oligocene Drowning, the uplift of Kā Tiritiri o te Moana, and forest habitat contraction and fragmentation during the Last Glacial Maximum.

Alafranji, Z. R., Morisawa, R., Aspholm, P. L., Fu, P. A., W. Moyes, N. H., A. Heine, H. L., Hejmadi, S. R., Derkarabetian, S., & Boyer, S. L. (2026). Biogeography of the widespread Aotearoa New Zealand mite harvester genus Rakaia (Arachnida, Opiliones, Cyphophthalmi) based on UCE-derived subgenomic data. Systematic Entomology, 51(1), e70021. https://doi.org/10.1111/syen.70021