Bacterial diversity in tropical glacier and glacier foreland in Uganda : Glacier ecosystem influence soil formation in glacier foreland

第6回極域科学シンポジウム[OB] 極域生物圏11月16日（月）　国立極地研究所１階交流アトリウ

Availability of a remote online hemodynamic monitoring system during treatment in a private dental office for medically high-risk patients

The importance of systemic management to prevent accidents is increasing in dentistry because co-morbid illnesses in an aging society and invasive surgical procedures are increasing. In this prefecture, a new medical system called the remote online hemodynamic monitoring system (ROHMs) was started in 2001. Eight private dental offices participated in this trial. When dental practitioners feel the risk of a dental procedure, they can contact via ROHMs to this hospital. Then, the hemodynamic data (blood pressure, heart rate, ECG, SpO2, and RPP) of the patient in the clinic can be transmitted here via the internet, and the images and the voice can be transmitted as well. The availability of this system was assessed in 66 patients (98 cases). The most frequent complications were hypertension, heart disease, and diabetes mellitus. Systemic management included monitoring during the dental procedure (71.4%), checking vital signs after an interview (15.3%), and monitoring under sedation (13.3%). There were 35.7% of all cases where an unscheduled procedure was necessary for the systemic management. Based on a questionnaire, the majority of the patients felt relieved and safe. This system creates a situation where a specialist is almost present during the procedure. This system will provide significant assistance for future medical cooperation for risk management

Effects of dissolved oxygen and pH on nitrous oxide production rates in autotrophic partial nitrification granules

The effects of dissolved oxygen (DO) and pH on nitrous oxide (N2O) production rates and pathways in autotrophic partial nitrification (PN) granules were investigated at the granular level. N2O was primarily produced by betaproteobacterial ammonia-oxidizing bacteria, mainly Nitrosomonas europaea, in the oxic surface layer (<200 μm) of the autotrophic PN granules. N2O production increased with increasing bulk DO concentration owing to activation of the ammonia (i.e., hydroxylamine) oxidation in this layer. The highest N2O emissions were observed at pH 7.5, although the ammonia oxidation rate was unchanged between pH 6.5 and 8.5. Overall, the results of this study suggest that in situ analyses of PN granules are essential to gaining insight into N2O emission mechanisms in a granule

Spatial distribution of cryoconite granules and microorganisms on Qaanaaq Glacier, Greenland

第6回極域科学シンポジウム分野横断セッション：[IB2] 地球環境変動の解析と地球生命システム学の構築11月19日（木）　統計数理研究所 セミナー室1（D305

Ancient DNA reveals multiple origins and migration waves of extinct Japanese brown bear lineages.

Little is known about how mammalian biogeography on islands was affected by sea-level fluctuations. In the Japanese Archipelago, brown bears (Ursus arctos) currently inhabit only Hokkaido, the northern island, but Pleistocene fossils indicate a past distribution throughout Honshu, Japan's largest island. However, the difficulty of recovering ancient DNA from fossils in temperate East Asia has limited our understanding of their evolutionary history. Here, we analysed mitochondrial DNA from a 32 500-year-old brown bear fossil from Honshu. Our results show that this individual belonged to a previously unknown lineage that split approximately 160 Ka from its sister lineage, the southern Hokkaido clade. This divergence time and fossil record suggest that brown bears migrated from the Eurasian continent to Honshu at least twice; the first population was an early-diverging lineage (greater than 340 Ka), and the second migrated via Hokkaido after approximately 160 Ka, during the ice age. Thus, glacial-age sea-level falls might have facilitated migrations of large mammals more frequently than previously thought, which may have had a substantial impact on ecosystem dynamics in these isolated islands

Genomic Analyses of Bifidobacterium moukalabense Reveal Adaptations to Frugivore/Folivore Feeding Behavior

Funding: This research was funded by the Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA), grant for the Science and Technology Research Partnership for Sustainable Development (SATREPS) “Conservation of Biodiversity in Tropical Forest through Sustainable Coexistence between Human and Wild Animals” (PI, Juichi Yamagiwa) and the study was also supported by Grants-in-Aid for Scientific Research (15K18775, Sayaka Tsuchida)”. Acknowledgments: We thank Ayumi Akiyoshi and Chiaki Hagiwara for technical assistance and Takahiro Yonezawa at Tokyo University of Agriculture for his valuable discussion about genetic evolution of Bifidobacterium. The authors are indebted for the sampling to Juichi Yamagiwa (Kyoto University), Yuji Takenoshita (Chubu Gakuin University), Shiho Fujita (Kagoshima University), Ludovic Ngok Banak and Alfred Ngomanda, the former and the actual Director of the Research Institute of Tropical Ecology (IRET)/National Center of Scientific Research and Technology (CENAREST) of Gabonese Republic. Takahiro Segawa was supported by Transdisciplinary Research Integration Center (TRIC) of the Research Organization of Information and Systems. Ortholog analyses were supported by Basis for Supporting Innovative Drug Discovery and Life Science Research program (2051). Computations were partially performed on the NIG (National Institute of Genetics) supercomputer at ROIS (Research Organization of Information and Systems) National Institute of Genetics.Peer reviewe

Metagenomics reveals global-scale contrasts in nitrogen cycling and cyanobacterial light-harvesting mechanisms in glacier cryoconite

BACKGROUND: Cryoconite granules are mineral–microbial aggregates found on glacier surfaces worldwide and are hotspots of biogeochemical reactions in glacier ecosystems. However, despite their importance within glacier ecosystems, the geographical diversity of taxonomic assemblages and metabolic potential of cryoconite communities around the globe remain unclear. In particular, the genomic content of cryoconite communities on Asia’s high mountain glaciers, which represent a substantial portion of Earth’s ice masses, has rarely been reported. Therefore, in this study, to elucidate the taxonomic and ecological diversities of cryoconite bacterial consortia on a global scale, we conducted shotgun metagenomic sequencing of cryoconite acquired from a range of geographical areas comprising Polar (Arctic and Antarctic) and Asian alpine regions. RESULTS: Our metagenomic data indicate that compositions of both bacterial taxa and functional genes are particularly distinctive for Asian cryoconite. Read abundance of the genes responsible for denitrification was significantly more abundant in Asian cryoconite than the Polar cryoconite, implying that denitrification is more enhanced in Asian glaciers. The taxonomic composition of Cyanobacteria, the key primary producers in cryoconite communities, also differs between the Polar and Asian samples. Analyses on the metagenome-assembled genomes and fluorescence emission spectra reveal that Asian cryoconite is dominated by multiple cyanobacterial lineages possessing phycoerythrin, a green light-harvesting component for photosynthesis. In contrast, Polar cryoconite is dominated by a single cyanobacterial species Phormidesmis priestleyi that does not possess phycoerythrin. These findings suggest that the assemblage of cryoconite bacterial communities respond to regional- or glacier-specific physicochemical conditions, such as the availability of nutrients (e.g., nitrate and dissolved organic carbon) and light (i.e., incident shortwave radiation). CONCLUSIONS: Our genome-resolved metagenomics provides the first characterization of the taxonomic and metabolic diversities of cryoconite from contrasting geographical areas, highlighted by the distinct light-harvesting approaches of Cyanobacteria and nitrogen utilization between Polar and Asian cryoconite, and implies the existence of environmental controls on the assemblage of cryoconite communities. These findings deepen our understanding of the biodiversity and biogeochemical cycles of glacier ecosystems, which are susceptible to ongoing climate change and glacier decline, on a global scale. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40168-022-01238-7

High-Throughput flaA Short Variable Region Sequencing to Assess Campylobacter Diversity in Fecal Samples From Birds

Current approach to identify sources of human pathogens is largely dependent on the cultivation and isolation of target bacteria. For rapid pathogen source identification, culture-independent strain typing method is necessary. In this study, we designed new primer set that broadly covers flaA short variable region (SVR) of various Campylobacter species, and applied the flaA SVR sequencing method to examine the diversity of Campylobacter spp. in geese fecal samples (n = 16) with and without bacteria cultivation. Twenty-three Campylobacter strains isolated from the 16 geese fecal samples were grouped similarly by conventional flaA restriction fragment length polymorphism (RFLP) method and by the flaA SVR sequencing method, but higher discriminant power was observed in the flaA SVR sequencing approach. For culture-independent flaA SVR sequencing analysis, we developed and optimized the sequence data analysis pipeline to identify as many genotypes as possible, while minimizing the detection of genotypes generated by sequencing errors. By using this pipeline, 51,629 high-quality flaA sequence reads were clustered into 16 operational taxonomic units (=genotypes) by using 98% sequence similarity and &gt;50 sequence duplicates. Almost all flaA genotypes obtained by culture-dependent method were also identified by culture-independent flaA SVR MiSeq sequencing method. In addition, more flaA genotypes were identified probably due to high throughput nature of the MiSeq sequencing. These results suggest that the flaA SVR sequencing could be used to analyze the diversity of Campylobacter spp. without bacteria isolation. This method is promising to rapidly identify potential sources of Campylobacter pathogens

Astrocytic dysfunction induced by ABCA1 deficiency causes optic neuropathy

Astrocyte abnormalities have received great attention for their association with various diseases in the brain but not so much in the eye. Recent independent genome-wide association studies of glaucoma, optic neuropathy characterized by retinal ganglion cell (RGC) degeneration, and vision loss found that single-nucleotide polymorphisms near the ABCA1 locus were common risk factors. Here, we show that Abca1 loss in retinal astrocytes causes glaucoma-like optic neuropathy in aged mice. ABCA1 was highly expressed in retinal astrocytes in mice. Thus, we generated macroglia-specific Abca1-deficient mice (Glia-KO) and found that aged Glia-KO mice had RGC degeneration and ocular dysfunction without affected intraocular pressure, a conventional risk factor for glaucoma. Single-cell RNA sequencing revealed that Abca1 deficiency in aged Glia-KO mice caused astrocyte-triggered inflammation and increased the susceptibility of certain RGC clusters to excitotoxicity. Together, astrocytes play a pivotal role in eye diseases, and loss of ABCA1 in astrocytes causes glaucoma-like neuropathy

氷床アイスコアや絶滅生物の遺伝子分析から見えてきた古代DNA解析

第6回極域科学シンポジウム分野横断セッション：[IB2] 地球環境変動の解析と地球生命システム学の構築11月19日（木）　統計数理研究所 セミナー室1（D305