151 research outputs found

    Spherulitic Textures Found in Pyrophyllite Ore Deposits, Shobara District, Southwest Japan: Photograph Collection

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    Spherulitic textures are commonly found in pyrophyllite ore deposits in Shobara district, Hiroshima Prefecture, Japan. Color photographs of the mode of occurrence, hand specimens and characteristic micro-textures are presented. The spherulitic textures occur mainly in the upper most horizon of the ore deposits, i.e., in pyrophyllite zone and weakly altered host rhyolitic rocks. The size of the spherulites is from few millimeters to several centimeters in diameter and the spherulites with several millimeters diameter is the most predominant. Color of the spherulites is also variable such as grey, dark blue, dark purple and greenish color. Under the microscope, the textures can be divided into two types, one is "radiation" and the other is "aggregation" types, respectively. The aggregation type is further subdivided into a) with fine grain rim and b) with coarse grain rim. The constituent minerals of the spherulite are feldspar, quartz, pyrophyllite, sericite, diaspore, hematite and goethite

    Tissue-specific expression of histone H3 variants diversified after species separation

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    Additional file 3: Predicted CDS of human histone H3/H4 variants, contains Table S2, which lists the CDS locus information of the predicted human histone H3 and H4 variants in an Excel file

    Homologs of plant PsbP and PsbQ proteins are necessary for regulation of photosystem II activity in the cyanobacterium Synechocystis 6803 W inside box sign

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    The mechanism of oxygen evolution by photosystem II (PSII) has remained highly conserved during the course of evolution from ancestral cyanobacteria to green plants. A cluster of manganese, calcium, and chloride ions, whose binding environment is optimized by PSII extrinsic proteins, catalyzes this water-splitting reaction. The accepted view is that in plants and green algae, the three extrinsic proteins are PsbO, PsbP, and PsbQ, whereas in cyanobacteria, they are PsbO, PsbV, and PsbU. Our previous proteomic analysis established the presence of a PsbQ homolog in the cyanobacterium Synechocystis 6803. The current study additionally demonstrates the presence of a PsbP homolog in cyanobacterial PSII. Both psbP and psbQ inactivation mutants exhibited reduced photoautotrophic growth as well as decreased water oxidation activity under CaCl2-depleted conditions. Moreover, purified PSII complexes from each mutant had significantly reduced activity. In cyanobacteria, one PsbQ is present per PSII complex, whereas PsbP is significantly substoichiometric. These findings indicate that both PsbP and PsbQ proteins are regulators that are necessary for the biogenesis of optimally active PSII in Synechocystis 6803. The new picture emerging from these data is that five extrinsic PSII proteins, PsbO, PsbP, PsbQ, PsbU, and PsbV, are present in cyanobacteria, two of which, PsbU and PsbV, have been lost during the evolution of green plants

    Differential lactate and cholesterol synthetic activities in XY and XX Sertoli cells

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    SRY, a sex-determining gene, induces testis development in chromosomally female (XX) individuals. However, mouse XX Sertoli cells carrying Sry (XX/Sry Sertoli cells) are incapable of fully supporting germ cell development, even when the karyotype of the germ cells is XY. While it has therefore been assumed that XX/Sry Sertoli cells are not functionally equivalent to XY Sertoli cells, it has remained unclear which specific functions are affected. To elucidate the functional difference, we compared the gene expression of XY and XX/Sry Sertoli cells. Lactate and cholesterol metabolisms, essential for nursing the developing germ cells, were down-regulated in XX/Sry cells, which appears to be caused at least in part by the differential expression of histone modification enzymes SMCX/SMCY (H3K4me3 demethylase) and UTX/UTY (H3K27me3 demethylase) encoded by the sex chromosomes. We suggest that down-regulation of lactate and cholesterol metabolism that may be due to altered epigenetic modification affects the nursing functions of XX/Sry Sertoli cells.This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 21249018 and 16H05142 (K. Mo.), Ministry of Education, Culture, Sports, Science, and Technology, Japan (MEXT) KAKENHI Grant Number 22132002 (K. Mo.), the Uehara Memorial Foundation, and Takeda Science Foundation (T.B.)

    H4K20me1 and H3K27me3 are concurrently loaded onto the inactive X chromosome but dispensabe for inducing gene silencing

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    © 2021 EMBO. This is an open access article under the terms of the Creative Commons Attribution License,which permits use, distribution and reproduction in any medium, provided the original work is properly cited.During X chromosome inactivation (XCI), in female placental mammals, gene silencing is initiated by the Xist long non-coding RNA. Xist accumulation at the X leads to enrichment of specific chromatin marks, including PRC2-dependent H3K27me3 and SETD8-dependent H4K20me1. However, the dynamics of this process in relation to Xist RNA accumulation remains unknown as is the involvement of H4K20me1 in initiating gene silencing. To follow XCI dynamics in living cells, we developed a genetically encoded, H3K27me3-specific intracellular antibody or H3K27me3-mintbody. By combining live-cell imaging of H3K27me3, H4K20me1, the X chromosome and Xist RNA, with ChIP-seq analysis we uncover concurrent accumulation of both marks during XCI, albeit with distinct genomic distributions. Furthermore, using a Xist B and C repeat mutant, which still shows gene silencing on the X but not H3K27me3 deposition, we also find a complete lack of H4K20me1 enrichment. This demonstrates that H4K20me1 is dispensable for the initiation of gene silencing, although it may have a role in the chromatin compaction that characterises facultative heterochromatin.This work was supported by Fundação para a Ciência e Tecnologia (S.T.d.R), project grants PTDC/BIA‐ MOL/29320/2017 IC&DT (A. C. R. & S.T.d.R), CEECUIND/01234/207 (S.T.d.R), and SFRH/BD/137099/2018 (A.C.R.), by an ERC Advanced Investigator award ERC‐ADG‐2014 671027 attributed to E.H., Sir Henry Wellcome Postdoctoral Fellowship (J.J.Z.), Japan Society for the Promotion of Science KAKENHI grants (JP17KK0143 and JP20K06484 to Y.S., JP19H04970, JP19H03158 and JP20H05393 to K.M., JP17K17719 to T.H., JP18H05534 to H.Ku, JP18H05527 and JP20H00456 to Y.O., JP17H01417 and JP18H05527 to H.Ki), and Japan Science and Technology Agency (JST) CREST JPMJCR16G1 to T.K., H.Ku, Y.O. and H.Ki, PREST JPMJPR2026 to K.M., and ERATO JPMJER1901 to H.Ku. J.J.Z. is supported by core funding of The Novo Nordisk Foundation Center for Stem Cell Biology (Novo Nordisk Foundation grant number NNF17CC0027852). Open Access funding enabled and organized by Projekt DEAL.info:eu-repo/semantics/publishedVersio

    Testis-Specific Histone Variant H3t Gene Is Essential for Entry into Spermatogenesis

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    Jun Ueda, Akihito Harada, Takashi Urahama, Shinichi Machida, Kazumitsu Maehara, Masashi Hada, Yoshinori Makino, Jumpei Nogami, Naoki Horikoshi, Akihisa Osakabe, Hiroyuki Taguchi, Hiroki Tanaka, Hiroaki Tachiwana, Tatsuma Yao, Minami Yamada, Takashi Iwamoto, Ayako Isotani, Masahito Ikawa, Taro Tachibana, Yuki Okada, Hiroshi Kimura, Yasuyuki Ohkawa, Hitoshi Kurumizaka, Kazuo Yamagata, Testis-Specific Histone Variant H3t Gene Is Essential for Entry into Spermatogenesis, Cell Reports, Volume 18, Issue 3, 2017, Pages 593-600, ISSN 2211-1247, https://doi.org/10.1016/j.celrep.2016.12.065

    DECIGO pathfinder

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    DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article
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