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A major incident occurred at the Fukushima Daiichi Nuclear Power Station following the tsunami triggered by the Tohoku-Pacific Ocean Earthquake in March 2011, whereby seawater entered the torus room in the basement of the reactor building. Here, we identify and analyze the bacterial communities in the torus room water and several environmental samples. Samples of the torus room water (1 × 10 9 Bq 137 Cs/L) were collected by the Tokyo Electric Power Company Holdings from two sampling points between 30 cm and 1 m from the bottom of the room (TW1) and the bottom layer (TW2). A structural analysis of the bacterial communities based on 16S rRNA amplicon sequencing revealed that the predominant bacterial genera in TW1 and TW2 were similar. TW1 primarily contained the genus Limnobacter , a thiosulfate-oxidizing bacterium. γ-Irradiation tests on Limnobacter thiooxidans , the most closely related phylogenetically found in TW1, indicated that its radiation resistance was similar to ordinary bacteria. TW2 predominantly contained the genus Brevirhabdus , a manganese-oxidizing bacterium. Although bacterial diversity in the torus room water was lower than seawater near Fukushima, ~70% of identified genera were associated with metal corrosion. Latent environment allocation-an analytical technique that estimates habitat distributions and co-detection analyses-revealed that the microbial communities in the torus room water originated from a distinct blend of natural marine microbial and artificial bacterial communities typical of biofilms, sludge, and wastewater. Understanding the specific bacteria linked to metal corrosion in damaged plants is important for advancing decommissioning efforts., Importance: In the context of nuclear power station decommissioning, the proliferation of microorganisms within the reactor and piping systems constitutes a formidable challenge. Therefore, the identification of microbial communities in such environments is of paramount importance. In the aftermath of the Fukushima Daiichi Nuclear Power Station accident, microbial community analysis was conducted on environmental samples collected mainly outside the site. However, analyses using samples from on-site areas, including adjacent soil and seawater, were not performed. This study represents the first comprehensive analysis of microbial communities, utilizing meta 16S amplicon sequencing, with a focus on environmental samples collected from the radioactive element-containing water in the torus room, including the surrounding environments. Some of the identified microbial genera are shared with those previously identified in spent nuclear fuel pools in countries such as France and Brazil. Moreover, our discussion in this paper elucidates the correlation of many of these bacteria with metal corrosion., Competing Interests: The authors declare no conflict of interest.

The brain synaptic circuitry is formed as a result of pre-defined genetic programs and sensory experience during postnatal development. Perineuronal nets ensheath synaptic boutons and control several crucial features of the synapse physiology. Formation of the perineuronal net microstructure during the brain development remains largely unstudied. Here we provide a detailed quantitative description of the 3-dimensional geometry of the synapse and the surrounding perineuronal net in the mouse somatosensory cortex layer IV. We compare the morphology of the synapse+perineuronal net complex in the adult brain formed under normal conditions or in the whisker shaving model of somatosensory deprivation. We demonstrate that the sensory deprivation causes flattening of the 3D PNN mesh geometry and reduction of the VGAT-positive cluster volume in presynaptic boutons. These results reveal a mechanism of the sensory input-dependent synapse morphogenesis during the brain development., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Non-biting midges (Chironomidae) are known to inhabit a wide range of environments, and certain species can tolerate extreme conditions, where the rest of insects cannot survive. In particular, the sleeping chironomid Polypedilum vanderplanki is known for the remarkable ability of its larvae to withstand almost complete desiccation by entering a state called anhydrobiosis. Chromosome numbers in chironomids are higher than in other dipterans and this extra genomic resource might facilitate rapid adaptation to novel environments. We used improved sequencing strategies to assemble a chromosome-level genome sequence for P. vanderplanki for deep comparative analysis of genomic location of genes associated with desiccation tolerance. Using whole genome-based cross-species and intra-species analysis, we provide evidence for the unique functional specialization of Chromosome 4 through extensive acquisition of novel genes. In contrast to other insect genomes, in the sleeping chironomid a uniquely high degree of subfunctionalization in paralogous anhydrobiosis genes occurs in this chromosome, as well as pseudogenization in a highly duplicated gene family. Our findings suggest that the Chromosome 4 in Polypedilum is a site of high genetic turnover, allowing it to act as a 'sandbox' for evolutionary experiments, thus facilitating the rapid adaptation of midges to harsh environments., (© The Author(s) 2022. Published by Oxford University Press on behalf of NAR Genomics and Bioinformatics.)

Extremophiles often undergo marked changes in genomic architecture, likely as a result of adaptation to the harsh environments they inhabit. These changes can involve gene duplications that affect subsequent gene evolution and the regulation of gene expression. Excellent examples of this are provided by two non-biting chironomid midges (Diptera, Chironomidae): Polypedilum vanderplanki, which in its larval form can withstand almost complete water loss, and Belgica antarctica, which exhibits freeze tolerance. This review presents recent studies on the molecular adaptations and evolutionary features of these and other extremophile chironomid genomes, as well as biotechnological applications of a cell line derived from P. vanderplanki that can survive air-drying. We highlight the importance of genomics in identifying molecular pathways and genomic modifications associated with adaptation to extreme environmental conditions., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The ability of larvae of a non-biting midge Polypedilum vanderplanki (Chironomidae) to withstand complete desiccation is a remarkable natural example of adaptation to extreme environment. In anhydrobiosis the larvae lose up to 99.2% of water and stay in a dry form until rainfall in natural environment or up to several decades in laboratory maintaining ability to restore activity soon after rehydration [1]. In the desiccated state, the larvae tolerate a variety of abiotic stresses, including high radiation exposure (7000Gry of 60 Co gamma rays) [2]. Such a cross-resistance to desiccation and ionizing radiation is a characteristic of many anhydrobiotic organisms and believed to be based on similar molecular mechanisms. Microorganisms associated with the anhydrobiotic midge can also sustain desiccation and thus be radiation-resistant because desiccation-resistant prokaryotes are shown to be cross-resistant to ionizing radiation [3]. Microorganisms inhabiting larvae of the anhydrobiotic midge can also sustain desiccation and probably can sustain high doses of ionizing radiation. Therefore, it would be of interest to analyze the taxonomic and functional composition of microbiome of the anhydrobiotic midge. Sequencing data for the total DNA of anhydrobiotic organisms, which also contain reads derived from symbiotic microorganisms provide a promising opportunity to identify microorganisms with remarkable adaptation. It is known that at least some protective genes, such as late embryogenesis abundant (LEA) genes appeared in the genome of the midge by probable horizontal gene transfer from bacteria [1]. We performed shotgun sequencing of imago and larvae DNA samples using HiSeq 2000 and Genome Analyzer IIX System platforms. To assess microbiome diversity specific to anhydrobiotic midges, we analyzed Pool-seq data of the natural population of imago and Pool-seq data of final instar larvae. Data has been deposited in NCBI BioProject repository at NCBI under the accession number PRJNA659554 and consists of raw sequence data., Competing Interests: The authors wish to declare that there are no conflicts of interest whatsoever, be it financial or personal. Hence, none of this was perceived to have influenced the outcome of the research reported herein in this data article., (© 2020 The Authors.)