The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae)

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  The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae) Abstract The morphological characters of copulatory organs are the most important basis in spiders for identification. In theridiids, a vulva with four sac-like structures is mostly associated with the subfamily Hadrotarsinae but has never been recorded in Theridiinae. Based on specimens collected from subtropical forest canopies in China, a new Theridiinae genus that has four sac-like structures in the vulva is described: Sactheridion gen. nov., with the type species S. chuan gen. & sp. nov. from Sichuan Province, China. Photos, diagnosis, description, and a distribution map of the new genus and new species are provided. Hu, C., Yao, Z., Liu, J. & Xu, X. (2026) The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae). Zootaxa, 5884 (1), 167–175. http...

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