Evidence of venom variability associated with venom extraction interval in the monocled cobra (Naja kaouthia)

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  Evidence of venom variability associated with venom extraction interval in the monocled cobra (Naja kaouthia) Abstract Snake venom variability is a critical factor in antivenom production. Although several influencing factors have been studied, the impact of extraction interval on venom properties remains poorly understood. This study evaluated the effects of various extraction intervals on venom yield, the percentage of dry weight (%Dw), and composition in the monocled cobra ( Naja kaouthia ). Twenty-five captive snakes were randomly allocated to five groups, each undergoing a control extraction followed by a repeated extraction at 1, 4, 7, 10, or 14 days. Venom profiles were characterized using reversed-phase high-performance liquid chromatography (RP-HPLC) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Results indicated that while fresh venom yield remained stable across all intervals, %Dw significantly decreased in extractions performed between 1 and 10 days, ...

Genomic and Methylomic Signatures Associated With the Maintenance of Genome Stability and Adaptive Evolution in Two Closely Allied Wolf Spiders

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Genomic and Methylomic Signatures Associated With the Maintenance of Genome Stability and Adaptive Evolution in Two Closely Allied Wolf Spiders

ABSTRACT

Pardosa spiders, belonging to the wolf spider family Lycosidae, play a vital role in maintaining the health of forest and agricultural ecosystems due to their function in pest control. This study presents chromosome-level genome assemblies for two allied Pardosa species, P. laura and P. agraria. Both species' genomes show a notable expansion of helitron transposable elements, which contributes to their large genome sizes. Methylome analysis indicates that P. laura has higher overall DNA methylation levels compared to P. agraria. DNA methylation may not only aids in transposable element-driven genome expansion but also positively affects the three-dimensional organisation of P. laura after transposon amplification, thereby potentially enhancing genome stability. Genes associated with hyper-differentially methylated regions in P. laura (compared to P. agraria) are enriched in functions related to mRNA processing and energy production. Furthermore, combined transcriptome and methylome profiling has uncovered a complex regulatory interplay between DNA methylation and gene expression, emphasising the important role of gene body methylation in the regulation of gene expression. Comparative genomic analysis shows a significant expansion of cuticle protein and detoxification-related gene families in P. laura, which may improve its adaptability to various habitats. This study provides essential genomic and methylomic insights, offering a deeper understanding of the relationship between transposable elements and genome stability, and illuminating the adaptive evolution and species differentiation among allied spiders.

Zuo, Q., Wu, B., Sun, N., Ren, Y., Fan, Z., Wang, Y., Tan, B., Luo, B., Irfan, M., Huang, Q., Shen, J., & Zhang, S. Genomic and Methylomic Signatures Associated With the Maintenance of Genome Stability and Adaptive Evolution in Two Closely Allied Wolf Spiders. Molecular Ecology Resources, e14071. https://doi.org/10.1111/1755-0998.14071