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Spider venom is a natural source of diverse biomolecules, but due to technical limitations, only a small fraction has been studied. With the advancement of omics technologies, research on spider venom has broadened, greatly promoting systematic studies of spider venom. Agelena limbata is a common spider found in vegetation, known for constructing funnel-shaped webs, and feeding on insects such as Diptera and Homoptera. However, due to its small size and the difficulty in obtaining venom, the composition of Agelena limbata venom has never been studied. In this study, a transcriptomics approach was used to analyze the toxin components in the venom of Agelena limbata, resulting in the identification of 28 novel toxin-like sequences and 24 peptidases. Based on sequence similarity and differences in cysteine motifs, the 28-novel toxin-like sequences were classified into 10 superfamilies. According to the results annotated in the database, the 24 peptidases were divided into six distinct families, with the serine protease family being the most common. A phylogenetic tree was constructed using the toxin-like sequences of Agelena limbata along with Psechrus triangulus and Hippasa lycosina. An analysis of the structural domains and motifs of Agelena limbata was also conducted. The results indicated that Agelena limbata is more distantly related to the other two species of funnel-web spiders, and that the toxin superfamily IX has a unique function compared to the other superfamilies. This study reveals the components of the Agelena limbata venom, deepening our understanding of it, and through bioinformatics analysis, has identified unique functions of the toxin superfamilies, providing a scientific basis for the development of bioactive drugs in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Macrothelidae is a family of mygalomorph spiders containing the extant genera Macrothele and Vacrothele. China is an important center of diversity for Macrothele with 65 % of the known species occurring there. Previous work on Macrothele was able to uncover several important toxin compounds including Raventoxin which may have applications in biomedicine and agricultural chemistry. Despite the importance of Macrothele spiders, high-quality reference genomes are still lacking, which hinders our understanding and application of the toxin compounds. In this study, we assembled the genome of the Macrothele yani to help fill gaps in our understanding of toxin biology in this lineage of spiders to encourage the future study and applications of these compounds. The final assembled genome was 6.79 Gb in total length, had a contig N50 of 21.44 Mb, and scaffold N50 of 156.16 Mb. Hi-C scaffolding assigned 98.19 % of the genome to 46 pseudo-chromosomes with a BUSCO score of 95.7 % for the core eukaryotic gene set. The assembled genome was found to contain 75.62 % repetitive DNA and a total of 39,687 protein-coding genes were annotated making it the spider genome with highest number of genes. Through integrated analysis of venom gland transcriptomics and venom proteomics, a total of 194 venom toxins were identified, including 38 disulfide-rich peptide neurotoxins, among which 12 were ICK knottin peptides. In summary, we present the first high-quality genome assembly at the chromosomal level for any Macrothelidae spider, filling an important gap in our knowledge of these spiders. Such high-quality genomic data will be invaluable as a reference in resolving Araneae spider phylogenies and in screening different spider species for novel compounds applicable to numerous medical and agricultural applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Wolf spiders in the genus Lycosa are important pest predators in agroforestry ecosystems, capable of feeding on a wide range of pests through the use of complex venom which can to quickly immobilize and kill prey. Because of these characteristics the toxins in wolf spiders venom may prove to be natural sources for novel drug development and biopesticides. To better understand the toxins in Lycosa venom we sequenced the transcriptome from venom glands from an undescribed species of Lycosa and comparatively analyzed the data using known protein motifs. A series of 19 disulfide-rich peptide (DRP) toxin sequences were identified and categorized into seven groups based on the number and arrangement of cysteine residues. Notably, we identified three peptide sequences with low identity to any known toxin, which may be toxin peptides specific to this species of Lycosa. In addition, to further understand the evolutionary relationships of disulfide-rich peptide toxins in spider venom, we constructed phylogenetic trees of DRP toxins from three spiders species and found that the Lycosa sp. DRPs are comparatively diverse with previous research results. This study reveals the toxin diversity of wolf spiders (Lycosa sp.) at the transcriptomic level and provides initial insights into the evolution of DRP toxins in spiders, enriching our knowledge of toxin diversity and providing new compounds for functional studies., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled, “Transcriptome sequencing of wolf spider Lycosa sp. (Araneae: Lycosidae) venom glands provides insights into the evolution and diversity of disulfide-rich toxins”., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The highly sensitive detection of low-abundant apurinic/apyrimidinic endonuclease 1 (APE1) activity is of great significance for early diagnosis of disease and pathological research. Many methods for detecting APE1 based on isothermal nucleic acids amplification have been developed for improving its sensitivity. However, some of these methods have certain limitations, such as multiple reaction steps, narrow linear range, and complicated processes for fluorescent labeling. Herein, we develop a highly sensitive and label-free APE1 fluorescence detection method based on rolling circle amplification combined with G-quadruplex (RCA-G4). A hairpin probe (HP) labeled with the AP site can be recognized and cleaved by APE1, leading to the release of the primer sequence, which triggered RCA to produce long chain amplification products with a great amount of repeated sequences. The formed amplicon contains a series G-quadruplex structure, which can be combined with Thioflavin T (ThT) to produce fluorescence and achieve high sensitivity label-free detection of APE1. Benefit from the high amplification efficiency of RCA and the high fluorescence quantum yield of G-quadruplex/ThT, a detection limit as low as 1.52 × 10 -6 U/mL and the linear range from 2 × 10 -6 to 10 U/mL were obtained. The developed RCA-G4 method can be successfully used to detect APE1 in serum samples with a recovery from 96.3% to 105.7%. We believe that this approach is expected to play an important role in APE1-related disease research and drug development., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Sensitive, specific and rapid methods for detecting microRNAs (miRNAs) play critical roles in disease diagnosis and therapy. Enzyme-free amplification techniques based on DNAzyme assembly have recently been developed for the highly specific miRNA analysis. However, traditional DNAzyme-based assembly (free DNAzyme) amplifiers is mainly dependent on the target-induced split DNAzyme fragments to assemble into activated DNAzyme structures, which have made a compromise between the sensitivity and specificity due to the random diffusion of dissociative probes in a bulk solution with poor kinetics. Herein, based on a rationally designed DNA probe, we developed an intramolecular DNAzyme assembly (intra-DNAzyme) method to overcome these challenges. The miR-373 is used as model analyte for our current proof-of-concept experiments. Compared with the free-DNAzyme method, our method showed significantly improved analytical performance in terms of dynamic range, assay sensitivity and speed. This method can detect miR-373 specifically with a detection limit as low as 4.3 fM, which is about 83.7 times lower than the previous free-DNAzyme method. This intra-DNAzyme strategy would be of great value in both basic research and clinical diagnosis., (Copyright © 2021 Elsevier B.V. All rights reserved.)