The biogenesis pathway of tRNA-derived piRNAs in Bombyx germ cells.

Transfer RNAs (tRNAs) function in translational machinery and further serves as a source of short non-coding RNAs (ncRNAs). tRNA-derived ncRNAs show differential expression profiles and play roles in many biological processes beyond translation. Molecular mechanisms that shape and regulate their expression profiles are largely unknown. Here, we report the mechanism of biogenesis for tRNA-derived Piwi-interacting RNAs (td-piRNAs) expressed in Bombyx BmN4 cells. In the cells, two cytoplasmic tRNA species, tRNAAspGUC and tRNAHisGUG, served as major sources for td-piRNAs, which were derived from the 5\u27-part of the respective tRNAs. cP-RNA-seq identified the two tRNAs as major substrates for the 5\u27-tRNA halves as well, suggesting a previously uncharacterized link between 5\u27-tRNA halves and td-piRNAs. An increase in levels of the 5\u27-tRNA halves, induced by BmNSun2 knockdown, enhanced the td-piRNA expression levels without quantitative change in mature tRNAs, indicating that 5\u27-tRNA halves, not mature tRNAs, are the direct precursors for td-piRNAs. For the generation of tRNAHisGUG-derived piRNAs, BmThg1l-mediated nucleotide addition to -1 position of tRNAHisGUG was required, revealing an important function of BmThg1l in piRNA biogenesis. Our study advances the understanding of biogenesis mechanisms and the genesis of specific expression profiles for tRNA-derived ncRNAs

A Study of OVAL Scroll Compressor for Capacity Increase

In recent years, there has been demand for a large-capacity scroll compressor to reduce cost and improve performance. To increase the capacity of the scroll compressor, technology to expand the stroke volume without increasing the shell size is required. To expand the stroke volume, expanding the wrap height in the axial direction is most effective. However, the higher wrap height raises the stress on the wrap and causes the orbiting scroll to overturn. So, we started to study a new shape of wrap to expand the stroke volume in the horizontal direction. The base plate of an orbiting scroll is usually circular. However, the trajectory of the fixed scroll on the base plate of the orbiting scroll is not circular, so wasted space that is not useful for compression exists on the base plate. We devised an oval wrap to make the trajectory of the fixed scroll on the base plate circular and reduce this space. The radius of basic circle was constant regardless of the involute angle in the conventional wrap. On the other hand, we can make the wrap shape “oval” by changing the radius of the basic circle sinusoidally (every 180 degrees). In this conference, we will present the geometric theory of our new oval wrap and the experimental result of the prototype. The results are follows: (1) It is possible to increase the stroke volume by more than 20% with the oval wrap. (2) A prototype with the oval wrap operates stably, and compressor efficiency is equivalent to the conventional wrap

Increasing cell density globally enhances the biogenesis of Piwi-interacting RNAs in Bombyx mori germ cells.

Piwi proteins and their bound Piwi-interacting RNAs (piRNAs) are predominantly expressed in the germline and play crucial roles in germline development by silencing transposons and other targets. Bombyx mori BmN4 cells are culturable germ cells that equip the piRNA pathway. Because of the scarcity of piRNA-expressing culturable cells, BmN4 cells are being utilized for the analyses of piRNA biogenesis. We here report that the piRNA biogenesis in BmN4 cells is regulated by cell density. As cell density increased, the abundance of Piwi proteins and piRNA biogenesis factors was commonly upregulated, resulting in an increased number of perinuclear nuage-like granules where Piwi proteins localize. Along with these phenomena, the abundance of mature piRNAs also globally increased, whereas levels of long piRNA precursor and transposons decreased, suggesting that increasing cell density promotes piRNA biogenesis pathway and that the resultant accumulation of mature piRNAs is functionally significant for transposon silencing. Our study reveals a previously uncharacterized link between cell density and piRNA biogenesis, designates cell density as a critical variable in piRNA studies using BmN4 cell system, and suggests the alteration of cell density as a useful tool to monitor piRNA biogenesis and function

Interferometers for Displacement-Noise-Free Gravitational-Wave Detection

We propose a class of displacement- and laser-noise free gravitational-wave-interferometer configurations, which does not sense non-geodesic mirror motions and laser noises, but provides non-vanishing gravitational-wave signal. Our interferometer consists of 4 mirrors and 2 beamsplitters, which form 4 Mach-Zehnder interferometers. By contrast to previous works, no composite mirrors are required. Each mirror in our configuration is sensed redundantly, by at least two pairs of incident and reflected beams. Displacement- and laser-noise free detection is achieved when output signals from these 4 interferometers are combined appropriately. Our 3-dimensional interferometer configuration has a low-frequency response proportional to f^2, which is better than the f^3 achievable by previous 2-dimensional configurations.Comment: 5 pages, 4 figure

Analysis of subgingival microbiota in monozygotic twins with different severity and progression risk of periodontitis

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression

Biological interaction of alginetin

Alginetin is the major product formed from pentoses and hexurionic acids. Alginetin is producted by cooking process of food including pection, a naturally-occurring polysacharride found in many plants. However, the biological interaction and toxicity of alginetin are not known at all. The aim of the present study was to investigate the cellular actions of alginetin on rat thymic lymphocytes. The effects of alginetin on the cell were examined using flow cytometry with fluorescent probes. Alginetin increased cellular content of non-protein thiols ([NPT]i) and elevated intracellular Zn2+ levels ([Zn2+]i). Chelation of intracellular Zn2+ reduced the effect of alginetin on [NPT]i, and chelation of external Zn2+ almost completely diminished alginetin-induced elevation of [Zn2+]i, indicating that alginetin treatment increased Zn2+ influx. Increased [NPT]i and [Zn2+]i levels in response to alginetin were positively correlated. Alginetin protected cells against oxidative stress induced by hydrogen peroxide and Ca2+ overload by calcium ionophore. It is considered that the increases in [NPT]i and [Zn2+]i are responsible for the cytoprotective activity of alginetin because NPT attenuates oxidative stress and Zn2+ competes with Ca2+. Alginetin may be produced during manufacturing of jam, which may provide additional health benefits of jam

The intertidal macrobenthic fauna of the Hatakejima Experimental Field, Wakayama Prefecture, Japan, in 2019

ファイル差し替え（2021-05-17）Hatakejima Experimental Field is located in Tanabe Bay, Wakayama Prefecture, Japan, which is composed of Hatakejima Island and Komarujima Islet, connected to the former in low tide. Hatakejima Island was purchased by Kyoto University and was designated as the “Hatakejima Experimental Field” in 1968. The year 2019 marks the 50th year of the long-term surveys that have been formally conducted on the experimental field since 1969 (i.e., the Century of Research Project). We conducted a field survey to record the macrobenthic fauna of the experimental field in 2019. A total of 168 species of 11 phyla were recorded in this survey. In each phylum, the number of species is listed as follows in descending order: Mollusca (78 spp.), Arthropoda (27 spp.), Echinodermata (23 spp.), Annelida (21 spp.), Cnidaria (7 spp.), Porifera (3 spp.), Nemertea (3 spp.), Platyhelminthes (2 spp.), Chordata (2 spp.), Bryozoa (1 sp.), and Hemichordata (1 sp.). We also recorded and discussed the influence of recent environmental changes around the Hatakejima Experimental Field. Tropical sea urchin species disappeared in the winter of 2017–2018 following the large meander of the Kuroshio Current, which led to decreasing water temperatures. The population of the seagrass Zostera japonica drastically decreased on the western sandy shore of the island in 2019, most likely because of two big typhoons in September 2018. We must conduct continuous observations to aid the recovery of seagrass-associated communities and protect the experimental field to keep high biodiversity of macrobenthic fauna in the future

Genome-wide identification of short 2\u27,3\u27-cyclic phosphate-containing RNAs and their regulation in aging.

RNA molecules generated by ribonuclease cleavage sometimes harbor a 2\u27,3\u27-cyclic phosphate (cP) at their 3\u27-ends. Those cP-containing RNAs (cP-RNAs) form a hidden layer of transcriptome because standard RNA-seq cannot capture them as a result of cP\u27s prevention of an adapter ligation reaction. Here we provide genome-wide analyses of short cP-RNA transcriptome across multiple mouse tissues. Using cP-RNA-seq that can exclusively sequence cP-RNAs, we identified numerous novel cP-RNA species which are mainly derived from cytoplasmic tRNAs, mRNAs, and rRNAs. Determination of the processing sites of substrate RNAs for cP-RNA generation revealed highly-specific RNA cleavage events between cytidine and adenosine in cP-RNA biogenesis. cP-RNAs were not evenly derived from the overall region of substrate RNAs but rather from specific sites, implying that cP-RNAs are not from random degradation but are produced through a regulated biogenesis pathway. The identified cP-RNAs were abundantly accumulated in mouse tissues, and the expression levels of cP-RNAs showed age-dependent reduction. These analyses of cP-RNA transcriptome unravel a novel, abundant class of non-coding RNAs whose expression could have physiological roles