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This study examined the longer-term individual- and school-level changes in students 7 months after a 1-hour delay in school start time (SST). Two cohorts of grade 11 students (N = 227; 60.8% female, age = 17.0 [0.85]) at a residential high school in Hong Kong completed a questionnaire assessing sleep duration, insomnia symptoms, depression, anxiety, stress, and subjective well-being in 2017 and 2018, respectively. One of the cohorts was reassessed 7 months after the implementation of a delay in SST, from 07:30 am to 08:30 am (n = 83, 65.1% female). School-level data on breakfast consumption, attendance, tardiness, and health clinic visits were collected. Between-group and within-group prospective comparisons suggest that the delay in SST was associated with improved sleep duration, mental health, and life satisfaction. School-level data revealed increased breakfast consumption and decreased unexcused absences, tardiness, and clinic visits., (© The Author(s) 2024. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.) more...

Brassinosteroids (BRs) are steroid hormones that play key roles in plant development and defense. Our goal is to harness the extensive knowledge of the Arabidopsis BR signaling network to improve productivity in crop species. This first requires identifying components of the conserved network and their function in the target species. Here, we investigated the function of SlBIM1a, the closest tomato homolog of AtBIM1, which is highly expressed in fruit. SlBIM1a-overexpressing lines displayed severe plant and fruit dwarfism, and histological characterization of different transgenic lines revealed that SlBIM1a expression negatively correlated with fruit pericarp cell size, resulting in fruit size modifications. These growth phenotypes were in contrast to those found in Arabidopsis, and this was confirmed by the reciprocal ectopic expression of SlBIM1a/b in Arabidopsis and of AtBIM1 in tomato. These results determined that BIM1 function depends more on the recipient species than on its primary sequence. Yeast two-hybrid interaction studies and transcriptomic analyses of SlBIM1a-overexpressing fruit further suggested that SlBIM1a acts through its interaction with SlBZH1 to govern the transcriptional regulation of growth-related BR target genes. Together, these results suggest that SlBIM1a is a negative regulator of pericarp cell expansion, possibly at the crossroads with auxin and light signaling., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.) more...

Objective: to estimate temporal trends in handgrip strength (HGS) for older Japanese adults between 1998 and 2017., Design and Methods: adults aged 60-79 years were included. Annual nationally representative HGS data (n = 176,449) for the 19-year study period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in mean HGS were estimated by sample-weighted regression models relating the year of testing to mean HGS. National trends in absolute, percent and standardised HGS were estimated by a post-stratified population-weighting procedure. Temporal trends in variability were estimated as the ratio of coefficients of variation (CVs)., Results: collectively, there was a small improvement in mean HGS of 1.4 kg (95% confidence interval [CI]: 1.3-1.5), 4.5% (95%CI: 4.3-4.7) or 0.27 standard deviations (95%CI: 0.26-0.28) between 1998 and 2017. The rate of improvement progressively increased over time, with more recent values (post-2008) 1.5-fold larger than earlier values. Gender- and age-related temporal differences were negligible. Variability in HGS declined substantially over time (ratio of CVs [95%CI]: 0.88 [0.86-0.90]), with declines 1.9-fold larger in women compared to men and 1.7-fold larger in 70- to 79-year-olds compared to 60- to 69-year-olds., Conclusions: there has been a small, progressive improvement in mean HGS for older Japanese adults since 1998, which is suggestive of a corresponding improvement in strength capacity. The substantial decline in variability indicates that the improvement in mean HGS was not uniform across the population., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.) more...

The kisspeptin neuronal system, which consists of a neuropeptide kisspeptin and its receptor Gpr54, is considered in mammals a key factor of reproductive regulation, the so-called hypothalamic-pituitary-gonadal (HPG) axis. However, in nonmammalian vertebrates, especially in teleosts, existence of kisspeptin regulation on the HPG axis is still controversial. In this study, we applied multidisciplinary techniques to a teleost fish, medaka, and examined possible kisspeptin regulation on the HPG axis. First, we generated knockout medaka for kisspeptin-related genes and found that they show normal fertility, gonadal maturation, and expression of gonadotropins. Moreover, the firing activity of GnRH1 neurons recorded by the patch clamp technique was not altered by kisspeptin application. Furthermore, in goldfish, in vivo kisspeptin administration did not show any positive effect on HPG axis regulation. However, as kisspeptin genes are completely conserved among vertebrates except birds, we surmised that kisspeptin should have some important nonreproductive functions in vertebrates. Therefore, to discover novel functions of kisspeptin, we generated a gpr54-1:enhanced green fluorescent protein (EGFP) transgenic medaka, whose gpr54-1-expressing cells are specifically labeled by EGFP. Analysis of neuronal projection of gpr54-1:EGFP-expressing neurons showed that these neurons in the ventrolateral preoptic area project to the pituitary and are probably involved in endocrine regulation other than gonadotropin release. Furthermore, combination of deep sequencing, histological, and electrophysiological analyses revealed various novel neural systems that are under control of kisspeptin neurons-that is, those expressing neuropeptide Yb, cholecystokinin, isotocin, vasotocin, and neuropeptide B. Thus, our new strategy to genetically label receptor-expressing neurons gives insights into various kisspeptin-dependent neuronal systems that may be conserved in vertebrates., (Copyright © 2018 Endocrine Society.) more...

RAB5 is a small GTPase that acts in endosomal trafficking. In addition to canonical RAB5 members that are homologous to animal RAB5, land plants harbor a plant-specific RAB5, the ARA6 group, which regulates trafficking events distinct from canonical RAB5 GTPases. Here, we report that plant RAB5, both canonical and plant-specific members, accumulate at the interface between host plants and biotrophic fungal and oomycete pathogens. Biotrophic fungi and oomycetes colonize living plant tissues by establishing specialized infection hyphae, the haustorium, within host plant cells. We found that Arabidopsis thaliana ARA6/RABF1, a plant-specific RAB5, is localized to the specialized membrane that surrounds the haustorium, the extrahaustorial membrane (EHM), formed by the A. thaliana-adapted powdery mildew fungus Golovinomyces orontii Whereas the conventional RAB5 ARA7/RABF2b was also localized to the EHM, endosomal SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) and RAB5-activating proteins were not, which suggests that the EHM has modified endosomal characteristic. The recruitment of host RAB5 to the EHM was a property shared by the barley-adapted powdery mildew fungus Blumeria graminis f.sp. hordei and the oomycete Hyaloperonospora arabidopsidis, but the extrahyphal membrane surrounding the hypha of the hemibiotrophic fungus Colletotrichum higginsianum at the biotrophic stage was devoid of RAB5. The localization of RAB5 to the EHM appears to correlate with the functionality of the haustorium. Our discovery sheds light on a novel relationship between plant RAB5 and obligate biotrophic pathogens., (© The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.) more...

Soybeans exhibit a nitrogen-fixing symbiosis with soil bacteria of the genera Bradyrhizobium and Ensifer/Sinorhizobium in a unique organ, the root nodule. It is well known that nodulation of soybean is controlled by several host genes referred to as Rj (rj) genes. Among these genes, a dominant allele, Rj4, restricts nodulation with specific bacterial strains such as B. elkanii USDA61 and B. japonicum Is-34. These incompatible strains fail to invade the host epidermal cells as revealed by observations using DsRed-labeled bacteria. Here, we describe the molecular identification of the Rj4 gene by using map-based cloning with several mapping populations. The Rj4 gene encoded a thaumatin-like protein (TLP) that belongs to pathogenesis-related (PR) protein family 5. In rj4/rj4 genotype soybeans and wild soybeans, we found six missense mutations and two consecutive amino acid deletions in the rj4 gene as compared with the Rj4 allele. We also found, using hairy root transformation, that the rj4/rj4 genotype soybeans were fully complemented by the expression of the Rj4 gene. Whereas the expression of many TLPs and other PR proteins is induced by biotic/abiotic stress, Rj4 gene expression appears to be constitutive in roots including root nodules., (© The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.) more...

GNOM is one of the most characterized membrane trafficking regulators in plants, with crucial roles in development. GNOM encodes an ARF-guanine nucleotide exchange factor (ARF-GEF) that activates small GTPases of the ARF (ADP ribosylation factor) class to mediate vesicle budding at endomembranes. The crucial role of GNOM in recycling of PIN auxin transporters and other proteins to the plasma membrane was identified in studies using the ARF-GEF inhibitor brefeldin A (BFA). GNOM, the most prominent regulator of recycling in plants, has been proposed to act and localize at so far elusive recycling endosomes. Here, we report the GNOM localization in context of its cellular function in Arabidopsis thaliana. State-of-the-art imaging, pharmacological interference, and ultrastructure analysis show that GNOM predominantly localizes to Golgi apparatus. Super-resolution confocal live imaging microscopy identified GNOM and its closest homolog GNOM-like 1 at distinct subdomains on Golgi cisternae. Short-term BFA treatment stabilizes GNOM at the Golgi apparatus, whereas prolonged exposures results in GNOM translocation to trans-Golgi network (TGN)/early endosomes (EEs). Malformed TGN/EE in gnom mutants suggests a role for GNOM in maintaining TGN/EE function. Our results redefine the subcellular action of GNOM and reevaluate the identity and function of recycling endosomes in plants., (© 2014 American Society of Plant Biologists. All rights reserved.) more...

This study aims to clarify the enhancement effect on chromosomal aberrations via selective energy absorption by Cu atoms in cultured bone cancer cells with non-labelled Cu-pyruvaldehyde-bis(N(4)-methylsemicarbazone) (Cu-PTSM) and monochromatic X rays. The X rays having the energy of the Cu K-shell absorption edge arising from synchrotron radiation (KEK-PF) was used as radiation source. Cu-PTSM labelled with copper radionuclides has been developed for medical imaging using positron emission tomography (PET). Evidence clearly showed that the absorption of X rays in the Cu K-shell caused this enhancement. After cells were treated with 1000 nM Cu-PTSM, the enhancement ratio of the initial yield of isochromatid breaks caused by CuK-H X-ray irradiation to that by 200 kV(p) X rays was approximately 2.8. About 5.6 times of the remaining isochromatid breaks were observed at 4 h in Cu-PTSM treated samples irradiated with CuK-H X rays comparing to that with 200 kV(p) X rays. In this study, uniqueness in physical property such as Cu atom K-shell ionisation was applied for the enhancement of biological effects in cancer cells. more...

Although the highest radiosensitivity of cells in the M phase among the other cell phases, such as the G(1), S and G(2) phases, has been known, the exact mechanism of radiosensitivity in mitotic cells remains unclear. Recently, mitotic arrest caused by DNA-damaging reagents has been shown, and the molecular mechanism in the arrest has been discussed in detail. In this study, abnormal cell-cycle progression in the M phase was investigated when a single mitotic cell in each mitotic stage was irradiated with a 5.35 keV X-ray microbeam focused on the cell nucleus. An X-ray microbeam irradiation system installed at BL-27 in Photon Factory, High Energy Accelerator Research Organization (HEARO, Tsukuba) was used. HeLa cells, genetically modified and expressing enhanced green fluorescent protein-tagged aurora kinase B, were used as irradiated samples in order to recognise the stage of each cell in the M phase. Thus, 10 Gy irradiation concentrated at the nucleus of a single cell elongated the cell-cycle progression in the M phase by delaying the metaphase/anaphase transition. The dose dependence of the elongation of the M phase was also examined. An irregular distribution of DNA in anaphase cells was observed after irradiation. more...

Predispersal copulation and unpredictable environment facilitate the evolution of female-biased dispersal in species, where females are functionally monandrous. Females should migrate and reproduce over different habitats to spread their risks due to environmental fluctuation. On the other hand, males do not have to disperse because their risks are spread by their mating partners who produce their offspring in different habitats. However, when females are functionally polyandrous, it is expected that they will not contribute to spreading the male's risk extensively. Therefore, by simulation with the individual based model, the present study evaluated how female polyandry influences the sexual difference in dispersal timing. This model revealed that when females are polyandrous, the timing of female remating and sperm priority patterns have an important influence on the evolution of sex-biased dispersal. Particularly when female remating is not synchronized with dispersal or when last-male sperm precedence does not exist, female-biased dispersal is evolved. more...

The incorporation of a fusion of green fluorescent protein and tubulin-alpha 6 from Arabidopsis thaliana in root hairs of Lotus japonicus has allowed us to visualize and quantify the dynamic parameters of the cortical microtubules in living root hairs. Analysis of individual microtubule turnover in real time showed that only plus polymer ends contributed to overall microtubule dynamicity, exhibiting dynamic instability as the main type of microtubule behavior in Lotus root hairs. Comparison of the four standard parameters of in vivo dynamic instability--the growth rate, the disassembly rate, and the frequency of transitions from disassembly to growth (rescue) and from growth to disassembly (catastrophe)--revealed that microtubules in young root hairs were more dynamic than those in mature root hairs. Either inoculation with Mesorhizobium loti or purified M. loti lipochitin oligosaccharide signal molecules (Nod factors) significantly affected the growth rate and transition frequencies in emerging and growing root hairs, making microtubules less dynamic at a specific window after symbiotic inoculation. This response of root hair cells to rhizobial Nod factors is discussed in terms of the possible biological significance of microtubule dynamics in the early signaling events leading to the establishment and progression of the globally important Rhizobium/legume symbiosis. more...

Arabidopsis thaliana plants were stably transformed with DNA encoding green fluorescent protein and with sequences ensuring retention in the endoplasmic reticulum (ER). Confocal laser scanning microscopy shows fluorescent ER in many cells of seedlings so allowing developmental changes to be documented. The arrangement of the cortical ER changes as cells mature in the hypocotyl and root epidermis. In the root, cells that have completed expansion have reticulate cortical ER resembling the ER described in many previous studies. Expanding cells, however, show extensive perforated sheets of cortical ER which transform quite abruptly into a loose reticulum at the basipetal end of the elongation zone. The reticulum compacts in trichoblasts beginning at sites where root hairs are about to emerge. The compacted form is maintained throughout the hair until growth ceases and the open reticulate form returns. All forms of cortical ER are dynamic and we use a color overlay method to distinguish stable and moving structures in a single composite image. Reticulate ER continuously rearranges its polygonal layout and perforations move and change their shape in the ER sheets of younger cells. ER deeper in the cell (i.e. not close to the plasma membrane) moves more actively so that almost no tubules remain stable even over short periods of less than one minute. The function of the perforated sheets of cortical ER present in growing cells is unknown. more...

The cotyledon requirement for gibberellin-induced hypocotyl elongation of light-grown cucumber (Cucumis sativus L. cv. Aonaga-jibae) seedlings was studied. Gibberellin A7 was used. At the saturation dosage, gibberellin-induced elongation was roughly proportional to the amount of the cotyledon retained. The cotyledon dependence of gibberellin-induced elongation was most marked when decotylization was done at the time of gibberellin treatment or at 24 hr after it. However, when the time of decotylization was delayed by more than 24 hr after gibberellin treatment, the effect was not immediate, and gibberellin-induced elongation continued for a while at a higher rate than that of the control. Young hypocotyls were more sensitive to gibberellin than older hypocotyls and their cotyledon requirement for gibberellin-induced elongation was less. Covering the cotyledons with aluminum foil or treating them with N'-(3,4-dichlorophenyl)-N-methoxy-N-methylurea, a photosynthetic inhibitor, reduced the gibberellin effect. There was a quantitative relationship between the magnitude of the covered or the inhibitor-treated area of the cotyledon and gibberellin-induced elongation. This quantitative relationship paralleled that for decotylization. These results suggested that the cotyledon requirement of the hypocotyl for gibberellin-induced elongation is at least partly related to the photosynthetic activity of the cotyledons., (Copyright © 1980. The Japanese Society of Plant Physiologists.) more...

Effects of Sex Ratio Organism (SRO) on the development of embryonic cells of Drosophila melanogaster were studied in vitro. The single embryo culture technique and a histochemical staining method were employed to distinguish male embryo cultures from female ones. SRO-infected Zw(n) females were crossed to wild-type males, and their embryos were separately dissociated and cultured in vitro. Cell growth and differentiation in each culture were examined by phase contrast microscopy and described both qualitatively and quantitatively. Neurons, imaginal disk cells and plasmatocyte-like cells barely differentiated in male (Zw( n)/Y) cultures, whereas muscle and fatbody cells were not so severely affected. These symptoms were generally specific to male cultures. Female (Zw(n)/+) cultures were relatively normal. These observations are consistent with the results of mosaic analysis. The susceptibility of cells to SRO is discussed in relation to the dose of X chromosome in the cells. more...