Independent Control by Each Female Gamete Prevents the Attraction of Multiple Pollen Tubes

SummaryIn flowering plants, double fertilization is normally accomplished by the first pollen tube, with the fertilized ovule subsequently inhibiting the attraction of a second pollen tube. However, the mechanism of second-pollen-tube avoidance remains unknown. We discovered that failure to fertilize either the egg cell or the central cell compromised second-pollen-tube avoidance in Arabidopsis thaliana. A similar disturbance was caused by disrupting the fertilization-independent seed (FIS) class polycomb-repressive complex 2 (FIS-PRC2), a central cell- and endosperm-specific chromatin-modifying complex for gene silencing. Therefore, the two female gametes have evolved their own signaling pathways. Intriguingly, second-pollen-tube attraction induced by half-successful fertilization allowed the ovules to complete double fertilization, producing a genetically distinct embryo and endosperm. We thus propose that each female gamete independently determines second-pollen-tube avoidance to maximize reproductive fitness in flowering plants

Versatile whole-organ/body staining and imaging based on electrolyte-gel properties of biological tissues

Whole-organ/body three-dimensional (3D) staining and imaging have been enduring challenges in histology. By dissecting the complex physicochemical environment of the staining system, we developed a highly optimized 3D staining imaging pipeline based on CUBIC. Based on our precise characterization of biological tissues as an electrolyte gel, we experimentally evaluated broad 3D staining conditions by using an artificial tissue-mimicking material. The combination of optimized conditions allows a bottom-up design of a superior 3D staining protocol that can uniformly label whole adult mouse brains, an adult marmoset brain hemisphere, an ~1 cm3 tissue block of a postmortem adult human cerebellum, and an entire infant marmoset body with dozens of antibodies and cell-impermeant nuclear stains. The whole-organ 3D images collected by light-sheet microscopy are used for computational analyses and whole-organ comparison analysis between species. This pipeline, named CUBIC-HistoVIsion, thus offers advanced opportunities for organ- and organism-scale histological analysis of multicellular systems

HMG Domain Containing SSRP1 Is Required for DNA Demethylation and Genomic Imprinting in Arabidopsis

In Arabidopsis, DEMETER (DME) DNA demethylase contributes to reprogramming of the epigenetic state of the genome in the central cell. However, other aspects of the active DNA demethylation processes remain elusive. Here we show that Arabidopsis SSRP1, known as an HMG domain-containing component of FACT histone chaperone, is required for DNA demethylation and for activation and repression of many parentally imprinted genes in the central cell. Although loss of DNA methylation releases silencing of the imprinted FWA-GFP, double ssrp1-3;met1-3 mutants surprisingly showed limited activation of maternal FWA-GFP in the central cell, and only became fully active after several nuclear divisions in the endosperm. This behavior was in contrast to the dme-1;met1 double mutant in which hypomethylation of FWA-GFP by met1 suppressed the DNA demethylation defect of dme-1. We propose that active DNA demethylation by DME requires SSRP1 function through a distinctly different process from direct DNA methylation control

Data_Sheet_1_Clinical significance of anti-Epstein–Barr virus antibodies in systemic chronic active Epstein–Barr virus disease.PDF

Systemic chronic active Epstein–Barr virus disease (sCAEBV) is a rare and fatal neoplasm, involving clonally proliferating Epstein–Barr virus (EBV)-infected T cells or natural killer cells. Patients with sCAEBV have abnormal titers of anti-EBV antibodies in their peripheral blood, but their significance is unknown. We retrospectively investigated titers and their relationship with the clinical features of sCAEBV using the data collected by the Japanese nationwide survey. Eighty-four patients with sCAEBV were analyzed. The anti-EBV nuclear antigen (EBNA) antibody, targeting EBNA-expressing EBV-positive cells, was found in 87.5% of children (<15 years old), 73.7% of adolescents and young adults (15–39 years old), and 100% of adults (≥40 years old). Anti-EBNA antibody titers were significantly lower and anti-VCA-IgG antibody titers significantly higher in patients with sCAEBV than those in healthy controls (p < 0.0001). Patients with high anti-VCA-IgG and anti-early antigen-IgG antibody (antibodies against the viral particles) levels had significantly better 3-year overall survival rates than those with low titers, suggesting that patients with sCAEBV have a reduced immune response to EBV-infected cells.</p

Signal improved ultra-fast light-sheet microscope for large tissue imaging

Abstract Axially swept light-sheet microscope in conjunction with tissue clearing enables three-dimensional morphological investigation of millimeter-scaled tissues at isotropic sub-micron resolution. However, these microscopes suffer from low detection signal and slow imaging speed. Here we report a simple and efficient imaging platform that employs precise control of two fixed distant light-sheet foci for axial sweeping. This enables full field of view imaging at 40 frames per second, a four-fold improvement over the current state-of-the-art. In addition, in a particular frame rate, our method doubles the signal compared to the existing techniques. To augment the overall imaging performance, we also developed a deep learning based tissue information classifier that enables faster determination of tissue boundary. We demonstrated the performance of our imaging platform on various cleared tissue samples and delineated its robustness over a wide range of clearing protocols

Mental training for elementary school athletes : A practical study

The purpose of this study was to examine the longitudinal effects of mental training for junior athletes. Two male athletes in the six grade participated in twelve months of mental training. The mental training program was created from information obtained during interviews and the Diagnostic Inventory of Psychological-Competitive Ability for Athletes (DIPCA.3). The mental training program consists of goal setting, performance routines, relaxation, and logbook tasks. The main results are as follows: 1) Junior athletes can develop psychological problems. 2) Subjects increased their performance routine with pair and relaxation during competition. 3) Subjects\u27 DIPCA.3 scores increased after mental training. 4) Both subjects competed in a national tournament for elementary school athletes. These results suggest that mental training may be effective for elementary school junior athletes

Sports mental training for junior badminton athletes : Study of the effective means for junior athletes

The purpose of this study was to examine the effects of sports mental training (SMT) in junior badminton athletes, and to consider effective means of implementing SMT with junior athletes. Subjects included two females (junior high school students) and two males (elementary school students). SMT was carried out 23-25 times for one year, and comprised relaxation, goal setting, logbook tasks, and analysis of peak performance. The effect of SMT was measured using the Diagnostic Inventory of Psychological-Competitive Ability for Athletes (DIPCA.3) as well as comments from the trainers and subjects. There were initially some problems with subjects\u27 communication skills. Therefore, they were also trained in communication skills using a special method. The effect of SMT was as follows: 1) Total DIPCA.3 scores improved in all subjects. 2) Subjects reported that nervousness during matches was reduced. 3) Subjects got the best results in tournament. 4) The time subjects spent expressing their emotions, ideas, and impressions was shorter. In summary, SMT was quick and effective, and special training in communication skills could further improve the effects of SMT

descSPIM: an affordable and easy-to-build light-sheet microscope optimized for tissue clearing techniques

Abstract Despite widespread adoption of tissue clearing techniques in recent years, poor access to suitable light-sheet fluorescence microscopes remains a major obstacle for biomedical end-users. Here, we present descSPIM (desktop-equipped SPIM for cleared specimens), a low-cost ($20,000–50,000), low-expertise (one-day installation by a non-expert), yet practical do-it-yourself light-sheet microscope as a solution for this bottleneck. Even the most fundamental configuration of descSPIM enables multi-color imaging of whole mouse brains and a cancer cell line-derived xenograft tumor mass for the visualization of neurocircuitry, assessment of drug distribution, and pathological examination by false-colored hematoxylin and eosin staining in a three-dimensional manner. Academically open-sourced ( https://github.com/dbsb-juntendo/descSPIM ), descSPIM allows routine three-dimensional imaging of cleared samples in minutes. Thus, the dissemination of descSPIM will accelerate biomedical discoveries driven by tissue clearing technologies