Xylem K+ loading modulates K+ and Cs+ absorption and distribution in Arabidopsis under K+-limited conditions

Potassium (K+) is an essential macronutrient for plant growth. The transcriptional regulation of K+ transporter genes is one of the key mechanisms by which plants respond to K+ deficiency. Among the HAK/KUP/KT transporter family, HAK5, a high-affinity K+ transporter, is essential for root K+ uptake under low external K+ conditions. HAK5 expression in the root is highly induced by low external K+ concentration. While the molecular mechanisms of HAK5 regulation have been extensively studied, it remains unclear how plants sense and coordinates K+ uptake and translocation in response to changing environmental conditions. Using skor mutants, which have a defect in root-to-shoot K+ translocation, we have been able to determine how the internal K+ status affects the expression of HAK5. In skor mutant roots, under K+ deficiency, HAK5 expression was lower than in wild-type although the K+ concentration in roots was not significantly different. These results reveal that HAK5 is not only regulated by external K+ conditions but it is also regulated by internal K+ levels, which is in agreement with recent findings. Additionally, HAK5 plays a major role in the uptake of Cs+ in roots. Therefore, studying Cs+ in roots and having more detailed information about its uptake and translocation in the plant would be valuable. Radioactive tracing experiments revealed not only a reduction in the uptake of 137Cs+ and 42K+in skor mutants compared to wild-type but also a different distribution of 137Cs+ and 42K+ in tissues. In order to gain insight into the translocation, accumulation, and repartitioning of both K+ and Cs+ in plants, long-term treatment and split root experiments were conducted with the stable isotopes 133Cs+ and 85Rb+. Finally, our findings show that the K+ distribution in plant tissues regulates root uptake of K+ and Cs+ similarly, depending on HAK5; however, the translocation and accumulation of the two elements are different

Phosphate Import in Plants: Focus on the PHT1 Transporters

The main source of phosphorus for plants is inorganic phosphate (Pi), which is characterized by its poor availability and low mobility. Uptake of this element from the soil relies heavily upon the PHT1 transporters, a specific family of plant plasma membrane proteins that were identified by homology with the yeast PHO84 Pi transporter. Since the discovery of PHT1 transporters in 1996, various studies have revealed that their function is controlled by a highly complex network of regulation. This review will summarize the current state of research on plant PHT1 multigenic families, including physiological, biochemical, molecular, cellular, and genetics studies

Forebrain Ptf1a Is Required for Sexual Differentiation of the Brain

The mammalian brain undergoes sexual differentiation by gonadal hormones during the perinatal critical period. However, the machinery at earlier stages has not been well studied. We found that Ptf1a is expressed in certain neuroepithelial cells and immature neurons around the third ventricle that give rise to various neurons in several hypothalamic nuclei. We show that conditional Ptf1a-deficient mice (Ptf1a cKO) exhibit abnormalities in sex-biased behaviors and reproductive organs in both sexes. Gonadal hormone administration to gonadectomized animals revealed that the abnormal behavior is caused by disorganized sexual development of the knockout brain. Accordingly, expression of sex-biased genes was severely altered in the cKO hypothalamus. In particular, Kiss1, important for sexual differentiation of the brain, was drastically reduced in the cKO hypothalamus, which may contribute to the observed phenotypes in the Ptf1a cKO. These findings suggest that forebrain Ptf1a is one of the earliest regulators for sexual differentiation of the brain

Curated genome annotation of Oryza sativa ssp. japonica and comparative genome analysis with Arabidopsis thaliana

We present here the annotation of the complete genome of rice Oryza sativa L. ssp. japonica cultivar Nipponbare. All functional annotations for proteins and non-protein-coding RNA (npRNA) candidates were manually curated. Functions were identified or inferred in 19,969 (70%) of the proteins, and 131 possible npRNAs (including 58 antisense transcripts) were found. Almost 5000 annotated protein-coding genes were found to be disrupted in insertional mutant lines, which will accelerate future experimental validation of the annotations. The rice loci were determined by using cDNA sequences obtained from rice and other representative cereals. Our conservative estimate based on these loci and an extrapolation suggested that the gene number of rice is ~32,000, which is smaller than previous estimates. We conducted comparative analyses between rice and Arabidopsis thaliana and found that both genomes possessed several lineage-specific genes, which might account for the observed differences between these species, while they had similar sets of predicted functional domains among the protein sequences. A system to control translational efficiency seems to be conserved across large evolutionary distances. Moreover, the evolutionary process of protein-coding genes was examined. Our results suggest that natural selection may have played a role for duplicated genes in both species, so that duplication was suppressed or favored in a manner that depended on the function of a gene

大学を拠点とする多職種による子育て支援事業 “子育てコラボサロンどーなつ”の実践

　地域における子どもとその養育者の多様な悩みや問題に対応するために、看護学科と社会福祉学科の教員がそれぞれの専門性を活かして協働する子育て支援事業として、"子育てコラボサロンどーなつ″ を2018年度に開設した。 本稿は2019年度に実施した保育士・幼稚園等専門職を対象とする講座および子育て中の保護者を対象とする講座の活動内容、参加者およびボランティアとして参加した学生のアンケート結果をまとめて報告する。 講座の参加者はいずれの回も少人数であったものの、子どもと保護者が安心して参加し、講義や参加者同士の交流を通して子育てに前向きになれるような働きかけができた。 また、本事業のコンセプトである「多職種の専門性を活かした協働」と「大学を拠点とした活動」の強みを活かして「子育て支援のコミュニティ形成」に向けて一歩を踏み出すことができた

早期離床に対する看護師の認識と課題 －プロジェクトＦの活動を通じて－

早期離床を院内に定着させることを目標に，看護部でプロジェクトＦを発足させ活動を行った．まず，現状把握のため看護師538名に対し早期離床の認識についてのアンケート調査を行った．有効回答は428名（有効回答率79.6％）から得られた．その結果，離床援助技術の卒後の教育は不十分で，ほとんどの看護師が体位変換や移乗を困難であると感じていた．また，早期離床に関する医師の指示や離床に関する記録が統一されていないことがわかった．早期離床を妨げる要因として，記録などの多忙な業務や，痛みや循環変動，複数のラインなど患者の要因が挙げられた．看護師が行う早期離床の現実と理想との間に大きな乖離があり，現状に満足していない状況が示唆された．調査の結果から，「離床援助技術の教育」「早期離床フローチャートの策定と運用」「離床に関する記録整備」を課題とし，組織をあげて改善への取り組みを行った．その経緯についても加えて報告する．In order to establish early mobilization in the hospital, the "project F" was created in the Nursing Department and activities were started. A questionnaire was held regarding early wake-up and valid response were obtained from 428 out of 538 people. According to the results, factors such as busyness due to nursing records were one of the reasons that hindered this. As a result, post-graduate education for mobilization skills was inadequate, and most nurses felt it was difficult to change positions or transfer. It was also found that doctors' instructions regarding early mobilization, and records related to mobilization, were not unified. Factors that hindered early mobilization included diligent work such as nursing records, patient factors such as pain and circulatory fluctuations, and multiple lines. There was a big divergence between the reality, and the ideals of early mobilization performed by nurses, suggesting that they are not satisfied with the current situation. Based on the results of the survey, the issues were "education of mobilization assistance technology", "development and operation of early mobilization flowchart", and "maintenance of records concerning mobilization", and the entire organization worked on improvement. We will also report on the process

Identification of mutations through dominant screening for obesity using C57BL/6 substrains

The discovery of leptin substantiated the usefulness of a forward genetic approach in elucidating the molecular network regulating energy metabolism. However, no successful dominant screening for obesity has been reported, which may be due to the influence of quantitative trait loci between the screening and counter strains and the low fertility of obese mice. Here, we performed a dominant screening for obesity using C57BL/6 substrains, C57BL/6J and C57BL/6N, with the routine use of in vitro fertilization. The screening of more than 5000 mutagenized mice established two obese pedigrees in which single nucleotide substitutions in Mc4r and Sim1 genes were identified through whole-exome sequencing. The mutation in the Mc4r gene produces a premature stop codon, and the mutant SIM1 protein lacks transcriptional activity, showing that the haploinsufficiency of SIM1 and MC4R results in obesity. We further examined the hypothalamic neuropeptide expressions in the mutant pedigrees and mice with diet-induced obesity, which showed that each obesity mouse model has distinct neuropeptide expression profiles. This forward genetic screening scheme is useful and applicable to any research field in which mouse models work

Reviewing impacts of biotic and abiotic stresses on the regulation of phosphate homeostasis in plants

International audienc

Sulfur Deficiency Increases Phosphate Accumulation, Uptake, and Transport in Arabidopsis thaliana

Recent studies have shown various metabolic and transcriptomic interactions between sulfur (S) and phosphorus (P) in plants. However, most studies have focused on the effects of phosphate (Pi) availability and P signaling pathways on S homeostasis, whereas the effects of S availability on P homeostasis remain largely unknown. In this study, we investigated the interactions between S and P from the perspective of S availability. We investigated the effects of S availability on Pi uptake, transport, and accumulation in Arabidopsis thaliana grown under sulfur sufficiency (+S) and deficiency (−S). Total P in shoots was significantly increased under −S owing to higher Pi accumulation. This accumulation was facilitated by increased Pi uptake under −S. In addition, −S increased root-to-shoot Pi transport, which was indicated by the increased Pi levels in xylem sap under −S. The −S-increased Pi level in the xylem sap was diminished in the disruption lines of PHT1;9 and PHO1, which are involved in root-to-shoot Pi transport. Our findings indicate a new aspect of the interaction between S and P by listing the increased Pi accumulation as part of −S responses and by highlighting the effects of −S on Pi uptake, transport, and homeostasis