TY - JOUR A1 - Aumont, Cédric A1 - Beránková, T. A1 - McMahon, Dino Peter A1 - Radek, R. A1 - Akama, P. D. A1 - Sillam-Dussès, D. A1 - Sobotnik, J. ED - Scholtz, G. T1 - The ultrastructure of the rostral gland in soldiers of Verrucositermes tuberosus (Blattodea: Termitidae: Nasutitermitinae) N2 - The soil-feeding habit is an evolutionary novelty found in some advanced groups of termites. The study of such groups is important to revealing interesting adaptations to this way-of-life. The genus Verrucositermes is one such example, characterized by peculiar outgrowths on the head capsule, antennae and maxillary palps, which are not found in any other termite. These structures have been hypothesized to be linked to the presence of a new exocrine organ, the rostral gland, whose structure has remained unexplored. We have thus studied the ultrastructure of the epidermal layer of the head capsule of Verrucositermes tuberosus soldiers.We describe the ultrastructure of the rostral gland, which consists of class 3 secretory cells only. The dominant secretory organelles comprise rough endoplasmic reticulum and Golgi apparatus, which provide secretions delivered to the surface of the head, likely made of peptide-derived components of unclear function. We discuss a possible role of the rostral gland of soldiers as an adaptation to the frequent encounter with soil pathogens during search for new food resources. KW - Soil-feeding habit KW - Advanced groups of termites KW - New exocrine organ KW - Rostral gland KW - Epidemal layer KW - Peptide-derived components PY - 2023 DO - https://doi.org/10.1016/j.asd.2023.101238 SN - 1467-8039 VL - 73 SP - 1 EP - 5 PB - Elsevier Ltd. CY - London, UK AN - OPUS4-57046 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Protasov, E A1 - Noah, J O A1 - Kästle Silva, J O A1 - Mies, U S A1 - Hervé, V A1 - Dietrich, C A1 - Lang, K A1 - Mikulski, L A1 - Platt, K A1 - Poehlein, A A1 - Köhler-Ramm, T A1 - Miambi, E A1 - Boga, H I A1 - Feldewert, C A1 - Ngugi, G K A1 - Plarre, Rüdiger A1 - Sillam-Dussès, D A1 - Šobotník, J A1 - Daniel, R A1 - Brune, A T1 - Diversity and taxonomic revision of methanogens and other archaea in the intestinal tract of terrestrial arthropods N2 - Methane emission by terrestrial invertebrates is restricted to millipedes, termites, cockroaches, and scarab beetles. The arthropod-associated archaea known to date belong to the orders Methanobacteriales, Methanomassiliicoccales, Methanomicrobiales, and Methanosarcinales, and in a few cases also to nonmethanogenic Nitrososphaerales and Bathyarchaeales. However, all major host groups are severely undersampled, and the taxonomy of existing lineages is not well developed. Full-length 16S rRNA gene sequences and genomes of arthropod-associated archaea are scarce, reference databases lack resolution, and the names of many taxa are either not validly published or under-classified and require revision. Here, we investigated the diversity of archaea in a wide range of methane-emitting arthropods, combining phylogenomic analysis of isolates and metagenome-assembled genomes (MAGs) with amplicon sequencing of full-length 16S rRNA genes. Our results allowed us to describe numerous new species in hitherto undescribed taxa among the orders Methanobacteriales (Methanacia, Methanarmilla, Methanobaculum, Methanobinarius, Methanocatella, Methanoflexus, Methanorudis, and Methanovirga, all gen. nova), Methanomicrobiales (Methanofilum and Methanorbis, both gen. nova), Methanosarcinales (Methanofrustulum and Methanolapillus, both gen. nova), Methanomassiliicoccales (Methanomethylophilaceae fam. nov., Methanarcanum, Methanogranum, Methanomethylophilus, Methanomicula, Methanoplasma, Methanoprimaticola, all gen. nova), and the new family Bathycorpusculaceae (Bathycorpusculum gen. nov.). Reclassification of amplicon libraries from this and previous studies using this new taxonomic framework revealed that arthropods harbor only CO2 and methyl-reducing hydrogenotrophic methanogens. Numerous genus-level lineages appear to be present exclusively in arthropods,suggesting long evolutionary trajectories with their termite, cockroach, and millipede hosts, and a radiation into various microhabitats and ecological nichesprovided by their digestive tracts (e.g., hindgut compartments, gut wall, or anaerobic protists). The distribution patterns among the different host groups are often complex, indicating a mixed mode of transmission and a parallel evolution of invertebrate and vertebrate-associated lineages. KW - Nitrososphaerales KW - Archaea KW - Methanogens KW - Gut microbiota KW - Termites KW - Cockroaches KW - Millipedes KW - Bathyarchaeia PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588230 DO - https://doi.org/10.3389/fmicb.2023.1281628 SN - 1664-302X VL - 14 SP - 1 EP - 21 PB - Frontiers AN - OPUS4-58823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -