Three-dimensional nanoscale analysis of light-dependent organelle changes in Arabidopsis mesophyll cells

一つの植物細胞を丸ごと3次元で再現 --光依存的なオルガネラの変化をナノスケールで探る--. 京都大学プレスリリース. 2022-10-19.Different organelles function coordinately in numerous intracellular processes. Photorespiration incidental to photosynthetic carbon fixation is organized across three subcellular compartments: chloroplasts, peroxisomes, and mitochondria. Under light conditions, these three organelles often form a ternary organellar complex in close proximity, suggesting a connection with metabolism during photorespiration. However, due to the heterogeneity of intercellular organelle localization and morphology, organelles' responses to changes in the external environment remain poorly understood. Here we used array tomography by field emission scanning electron microscopy to image organelles inside the whole plant cell at nanometer resolution, generating a three-dimensional (3D) spatial map of the light-dependent positioning of chloroplasts, peroxisomes, nuclei, and vacuoles. Our results show, in light-treated cells, the volume of peroxisomes increased, and mitochondria were simplified. In addition, the population of free organelles decreased, and the ternary complex centered on chloroplasts increased. Moreover, our results emphasized the expansion of the proximity area rather than the increase in the number of proximity sites inter-organelles. All of these phenomena were quantified for the first time on the basis of nanoscale spatial maps. In summary, we provide the first 3D reconstruction of Arabidopsis mesophyll cells, together with nanoscale quantified organelle morphology and their positioning via proximity areas, and then evidence of their light-dependent changes

Water utilization situations at two suburban areas in Lao P.D,R. - The cases of Lahanam district, Savannakhet and its changing pattern in Xaithani district in Vienntiane Capital -

Utilization and availability of water source is a serious health problem in developing countries. To analyze local condition of water utilization patterns in Lao PDR, a comparative study on water utility and sanitation condition along the local context was conducted at 2 villages in Savannakhet province and a village in Vientiane Capital in 2005. There was no city water supply in the two areas. Water utilization and the sanitation data of the Capital village in 2000 were also employed to compare change of the situation for 6 years at the place. In Savannakhet, main water sources were dug well, river, purchase-bottle water, and rainwater storage. Rainwater was common drinking source, and a half of them drink before boiling. In the capital area, main water sources were well (borehole and dug wells), purchase-bottle water both in 2000 and in 2005. Utilization of drinking water, well water was chosen firstly and the water boiling practice rates were not so different in both areas. The consumption of purchase water was higher in Vientiane than in Savannakhet. Also, it was demonstrated that the rate of purchase water increased much at the capital in these six years

Electronic Endoscopy in Endoscopic Mucosal Resection (EMR) of Gastric Cancer

The role in which electronic endoscopy plays is important in EMR. It is useful in diagnosis and treatment of gastric cancer from a clinical viewpoint. EMR with use of electronic endoscopy allows better coordination between the operator and assistants, and thus improves the results further