Hurd, Paul J.Grubel, KorneliaWojciechowski, MarekMaleszka, RyszardRossler, Wolfgang2022-08-032022-08-032045-2322http://hdl.handle.net/1885/270171In the course of a screen designed to produce antibodies (ABs) with affinity to proteins in the honey bee brain we found an interesting AB that detects a highly specific epitope predominantly in the nuclei of Kenyon cells (KCs). The observed staining pattern is unique, and its unfamiliarity indicates a novel previously unseen nuclear structure that does not colocalize with the cytoskeletal protein f-actin. A single rod-like assembly, 3.7–4.1 µm long, is present in each nucleus of KCs in adult brains of worker bees and drones with the strongest immuno-labelling found in foraging bees. In brains of young queens, the labelling is more sporadic, and the rod-like structure appears to be shorter (~ 2.1 µm). No immunostaining is detectable in worker larvae. In pupal stage 5 during a peak of brain development only some occasional staining was identified. Although the cellular function of this unexpected structure has not been determined, the unusual distinctiveness of the revealed pattern suggests an unknown and potentially important protein assembly. One possibility is that this nuclear assembly is part of the KCs plasticity underlying the brain maturation in adult honey bees. Because no labelling with this AB is detectable in brains of the fly Drosophila melanogaster and the ant Camponotus floridanus, we tentatively named this antibody AmBNSab (Apis mellifera Brain Neurons Specific antibody). Here we report our results to make them accessible to a broader community and invite further research to unravel the biological role of this curious nuclear structure in the honey bee central brain.Open Access funding enabled and organized by Projekt DEAL. Biotechnology and Biological Sciences Research Council, BB/L023164/1. William Harvey International Translational Research Academy, WHRI-ACADEMY. H2020 Marie Skłodowska-Curie Actions, PCOFUND-GA-2013-608765. Deutsche Forschungsgemeinschaf, INST 93/829-1. Australian Research Council, DP160103053.application/pdfen-AU© 2021 The authorshttp://creativecommons.org/licenses/by/4.0/202110.1038/s41598-021-86078-52021-08-01Creative Commons