Ovophis tonkinensis envenoming presenting with severe isolated thrombocytopenia and local necrosis: A case report

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  Image Credit: iNaturalist (c) randall_f –  some rights reserved (CC BY-NC) Ovophis tonkinensis envenoming presenting with severe isolated thrombocytopenia and local necrosis: A case report Abstract Pit viper envenoming commonly causes venom-induced consumption coagulopathy with hypofibrinogenaemia. However, isolated thrombocytopenia without fibrinogen depletion is less recognised and may alter transfusion strategy. We report a confirmed  Ovophis tonkinensis  bite from northern Vietnam presenting with severe isolated thrombocytopenia and local necrosis. The case highlights the importance of serial platelet monitoring, awareness of fibrinogen availability and appropriate timing of antivenom and platelet support in resource-limited tropical settings. Duc ND, Hong Anh LN, Hong Khanh LN, Bach ND. Ovophis tonkinensis envenoming presenting with severe isolated thrombocytopenia and local necrosis: A case report. Tropical Doctor . 2026;0(0). doi: 10.1177/00494755261435153

The protamines of the noble false widow spider Steatoda nobilis provide an example of liquid-liquid phase separation chromatin transitions during spermiogenesis

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The protamines of the noble false widow spider Steatoda nobilis provide an example of liquid-liquid phase separation chromatin transitions during spermiogenesis

    Abstract

While there is extensive information about sperm nuclear basic proteins (SNBP) in vertebrates, there is very little information about Arthropoda by comparison. This paper aims to contribute to filling this gap by analyzing these proteins in the sperm of the noble false widow spider Steatoda nobilis (Order Araneae, Family Theridiidae). To this end, we have developed a protein extraction method that allows the extraction of cysteine-containing protamines suitable for the preparation and analysis of SNBPs from samples where the amount of starting tissue material is limited. We carried out top-down mass spectrometry sequencing and molecular phylogenetic analyses to characterize the protamines of S. nobilis and other spiders. We also used electron microscopy to analyze the chromatin organization of the sperm, and we found it to exhibit liquid-liquid phase spinodal decomposition during the late stages of spermiogenesis. These studies further our knowledge of the distribution of SNBPs within the animal kingdom and provide additional support for a proposed evolutionary origin of many protamines from a histone H1 (H5) replication-independent precursor.


The protamines of the noble false widow spider Steatoda nobilis provide an example of liquid-liquid phase separation chromatin transitions during spermiogenesis

Melissa R Leyden, Peter Michalik, Luciana Baruffaldi, Susheen Mahmood, Ladan Kalani, Donald F Hunt, Jose Maria Eirin-Lopez, Maydianne C.B. Andrade, Jeffrey Shabanowitz, Juan Ausió

bioRxiv 2024.06.04.597381; doi: https://doi.org/10.1101/2024.06.04.597381