Notes on the identity of the orb-weaver spider Araneus nox Simon, 1877 (Araneae: Araneidae) from India, including its transfer to Eriovixia Archer, 1951 and one new synonymy

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  Notes on the identity of the orb-weaver spider Araneus nox Simon, 1877 (Araneae: Araneidae) from India, including its transfer to Eriovixia Archer, 1951 and one new synonymy The orb-weaver genus Araneus Clerck, 1757 has historically served as a heterogeneous assemblage for numerous araneid spiders lacking clear generic placement, and several Asian species formerly assigned to Araneus have subsequently been transferred to more narrowly defined genera. One species that still needs further investigation on its true identity is Araneus nox (Simon, 1877), originally described as Epeira nox Simon, 1877 from Basilan Island, Philippines, and later transferred to Araneus by Simon (1905). In the same year as the description of Epeira nox, Thorell (1877) described Epeira pilula from the Moluccas (Indonesia), which was subsequently synonymised under Epeira nox by Simon (1880). Despite its broad Oriental distribution, the taxonomic identity and generic placement of A. nox have remained insuff...

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