Bipolar localization of putative photoreceptor protein for phototaxis in thermophilic cyanobacterium Synechococcus elongatus

Funding Information: This work was supported in part by Grants-in-Aid for scientific research from the Ministry of Education, Science, Sports and Culture, Japan (no. 11640653 to K.M.).We identified an open reading frame from a database of the entire genome of Synechococcus elongatus, the product of which was very similar to pixJ1, which was proposed as photoreceptor gene for phototaxis in Synechocystis sp. PCC6803 [Yoshihara et al. (2000) Plant Cell Physiol. 41: 1299]. The mRNA of S. elongatus pixJ (SepixJ) was expressed in vivo as a part of the product of an operon. SePixJ was detected exclusively in the membrane fraction after cell fractionation. Immunogold labeling of SePixJ in ultra-thin sections indicated that it existed only in both ends of the rod-shaped cell; probably bound with the cytoplasmic membrane.publishersversionPeer reviewe

High-Throughput Cryopreservation of Plant Cell Cultures for Functional Genomics

Suspension-cultured cell lines from plant species are useful for genetic engineering. However, maintenance of these lines is laborious, involves routine subculturing and hampers wider use of transgenic lines, especially when many lines are required for a high-throughput functional genomics application. Cryopreservation of these lines may reduce the need for subculturing. Here, we established a simple protocol for cryopreservation of cell lines from five commonly used plant species, Arabidopsis thaliana, Daucus carota, Lotus japonicus, Nicotiana tabacum and Oryza sativa. The LSP solution (2 M glycerol, 0.4 M sucrose and 86.9 mM proline) protected cells from damage during freezing and was only mildly toxic to cells kept at room temperature for at least 2 h. More than 100 samples were processed for freezing simultaneously. Initially, we determined the conditions for cryopreservation using a programmable freezer; we then developed a modified simple protocol that did not require a programmable freezer. In the simple protocol, a thick expanded polystyrene (EPS) container containing the vials with the cell–LSP solution mixtures was kept at −30°C for 6 h to cool the cells slowly (pre-freezing); samples from the EPS containers were then plunged into liquid nitrogen before long-term storage. Transgenic Arabidopsis cells were subjected to cryopreservation, thawed and then re-grown in culture; transcriptome and metabolome analyses indicated that there was no significant difference in gene expression or metabolism between cryopreserved cells and control cells. The simplicity of the protocol will accelerate the pace of research in functional plant genomics

Periportal hepatocyte proliferation at midgestation governs maternal glucose homeostasis in mice

Abstract The maternal liver is challenged by metabolic demands throughout pregnancy. However, hepatocyte dynamics and their physiological significance in pregnancy remain unclear. Here, we show in mice that hepatocyte proliferation is spatiotemporally regulated in each liver lobular zone during pregnancy, with transient proliferation of periportal and pericentral hepatocytes during mid and late gestation, respectively. Using adeno-associated virus (AAV)−8-mediated expression of the cell cycle inhibitor p21 in hepatocytes, we show that inhibition of hepatocyte proliferation during mid, but not late, gestation impairs liver growth. Transcriptionally, genes involved in glucose/glycogen metabolism are downregulated in late pregnancy when midgestational hepatocyte proliferation is attenuated. In addition, hepatic glycogen storage is abolished, with concomitant elevated blood glucose concentrations, glucose intolerance, placental glycogen deposition, and fetal overgrowth. Laser capture microdissection and RNA-seq analysis of each liver lobular zone show zone-specific changes in the transcriptome during pregnancy and identify genes that are periportally expressed at midgestation, including the hyaluronan-mediated motility receptor (Hmmr). Knockdown of Hmmr in hepatocytes by AAV8-shHmmr suppresses periportal hepatocyte proliferation at midgestation and induces impaired hepatic glycogen storage, glucose intolerance, placental glycogen deposition and fetal overgrowth. Our results suggest that periportal hepatocyte proliferation during midgestation is critical for maternal glycogen metabolism and fetal size

Effects of Different Exercise Conditions on Antioxidant Potential and Mental Assessment

Exercise increases oxidative stress, leading the body to strengthen its antioxidant defenses, thus reducing the incidence of major diseases. As these associations are relatively unclear for ordinary levels of exercise for reduced stress, this study evaluated the effects of different exercise conditions on diacron-reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and subjective mood. Forty-nine students (22.4 ± 2.6 years) were assessed using the Profile of Mood States (POMS) before and after exercising for 60 min. Participants were divided into two groups: Group A engaged in compulsory sports and Group B in freely chosen sports. d-ROMs and BAP were measured, and their modified ratio was calculated as an index of antioxidant potential. Physiological evaluation showed significant improvements in BAP and the BAP/d-ROMs ratio, irrespective of exercise condition (p p p p p < 0.03). Assessment of antioxidant status before and after exercise may provide an objective index of mental and physical conditioning

Effects of Different Exercise Conditions on Antioxidant Potential and Mental Assessment

Exercise increases oxidative stress, leading the body to strengthen its antioxidant defenses, thus reducing the incidence of major diseases. As these associations are relatively unclear for ordinary levels of exercise for reduced stress, this study evaluated the effects of different exercise conditions on diacron-reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and subjective mood. Forty-nine students (22.4 ± 2.6 years) were assessed using the Profile of Mood States (POMS) before and after exercising for 60 min. Participants were divided into two groups: Group A engaged in compulsory sports and Group B in freely chosen sports. d-ROMs and BAP were measured, and their modified ratio was calculated as an index of antioxidant potential. Physiological evaluation showed significant improvements in BAP and the BAP/d-ROMs ratio, irrespective of exercise condition (p &lt; 0.001, p &lt; 0.01). Comparison between the exercise conditions revealed a significant difference in the modified ratio (p &lt; 0.02). In mood assessment, scores on emotion-related scales without vigor improved significantly under both exercise conditions (p &lt; 0.001). Mental changes were evident after exercise, and potential antioxidant capacity was higher in freely chosen sports (p &lt; 0.03). Assessment of antioxidant status before and after exercise may provide an objective index of mental and physical conditioning