Shoot regeneration can be achieved in vitro through a two‐step process involving the acquisition of pluripotency on callus‐induction media (CIM) and the formation of shoots on shoot‐induction media. ...Although the induction of root‐meristem genes in callus has been noted recently, the mechanisms underlying their induction and their roles in de novo shoot regeneration remain unanswered. Here, we show that the histone acetyltransferase HAG1/AtGCN5 is essential for de novo shoot regeneration. In developing callus, it catalyzes histone acetylation at several root‐meristem gene loci including WOX5, WOX14, SCR, PLT1, and PLT2, providing an epigenetic platform for their transcriptional activation. In turn, we demonstrate that the transcription factors encoded by these loci act as key potency factors conferring regeneration potential to callus and establishing competence for de novo shoot regeneration. Thus, our study uncovers key epigenetic and potency factors regulating plant‐cell pluripotency. These factors might be useful in reprogramming lineage‐specified plant cells to pluripotency.
Synopsis
Shoot regeneration from Arabidopsis callus can be achieved via a two‐step process that involves pluripotency acquisition. The histone acetyltransferase HAG1/AtGCN5 is essential for de novo shoot formation by regulating pluripotency‐inducing transcription factors.
HAG1 targets several root meristem gene loci specifically in developing callus.
In callus, HAG1 reprograms and activates expression of root genes by histone acetylation.
The HAG1‐regulated root genes encode key potency factors essential for de novo shoot regeneration.
Expression of HAG1 and its target genes enhance the regeneration ability of plant cells.
Histone acetyltransferase activity in the developing callus is essential for de novo shoot regeneration by regulating key pluripotency factors.
Summary
During growth and development, plants undergo a series of phase transitions from the juvenile‐to‐adult vegetative phase to the reproductive phase. In Arabidopsis, vegetative phase transitions ...and flowering are regulated by SQUAMOSA PROMOTER BINDING PROTEIN‐LIKE (SPL) factors. SPL mRNAs are post‐transcriptionally regulated by miR156 in an age‐dependent manner; however, the role of other mechanisms in this process is not known. In this study, we demonstrate that the HAG1/GCN5‐ and PRZ1/ADA2b‐containing SAGA‐like histone acetyltransferase (HAT) complex directly controls the transcription of SPLs and determines the time for juvenile‐to‐adult phase transition. Thus, epigenetic control by the SAGA‐like HAT complex determines the transcriptional output of SPLs, which might be a prerequisite for the subsequent post‐transcriptional regulation by miR156. Importantly, this epigenetic control mechanism is also crucial for miR156‐independent induction of SPLs and acceleration of phase transition by light and photoperiod or during post‐embryonic growth.
Significance Statement
In Arabidopsis, the juvenile‐to‐adult phase transition is known to be controlled by SPL factors that are post‐transcriptionally regulated by miR156 in an age‐dependent manner. This study demonstrates that the HAG1/GCN5‐ and PRZ1/ADA2b‐containing SAGA‐like histone acetyltransferase complex directly determines the transcriptional output of SPLs required for the subsequent post‐transcriptional repression by miR156.
•Epidemiologic features of the second and third waves of the coronavirus disease 2019 (COVID-19) pandemic in South Korea were compared.•Strengthening of social distancing policies was delayed in the ...third wave compared with the second wave.•The third wave persisted longer than the second wave, and had a higher case fatality rate.•Early public health intervention is important to control the COVID-19 pandemic.
To compare epidemiologic features of the second and third waves of the coronavirus disease 2019 (COVID-19) pandemic in South Korea.
Nationwide COVID-19 data were collected between 6 May and 30 December 2020. The degree of social activity was estimated using an Internet search trend analysis program for leisure-related keywords, including ‘eating-out’, ‘trip’ and ‘get directions’ (transportation). Demographics, transmission chains, case fatality rates, social activity levels and public health responses were compared between the second (13 August–18 September 2020) and third (4 November 2020–present) waves.
In comparison with the second wave, the third wave was characterized by delayed strengthening of social distancing policies (3 vs. 15 days), longer duration (36 vs. >56 days) and a higher case fatality rate (0.91% vs. 1.26%). There were significant differences in transmission chains between the second and third waves (P < 0.01). In comparison with the second wave, the proportion of local clusters (24.8% vs. 45.7%) was lower in the third wave, and personal contact transmission (38.5% vs. 25.9%) and unknown routes of transmission (23.5% vs. 20.8%) were higher in the third wave.
Early and timely interventions with strengthened social distancing policies should be implemented to suppress and control the COVID-19 pandemic effectively.
Sitting for an extended time may cause a serious chronic disease such as a musculoskeletal disorder, or a cardiovascular disease, diabetes, or obesity. Because a consistently improper posture from ...early childhood to adolescence can have a number of undesirable effects on the formation of the musculoskeletal structure, learning to maintain a correct posture should be emphasized. A consistently improper posture can not only cause physical problems, it may also lead to emotional issues such as distractions, an attention deficit, and hyperactivity, and the possibility of a low efficiency and performance on assignments is high when the students have a low concentration. The present study implemented a distracted estimation system based on sensor fusion through correlation analysis with concentration that could estimate the level of distraction and prevent musculoskeletal diseases caused by poor sitting posture habits in daily life. The implemented system was designed in the form of a sitting cushion to reflect the ethological movements and characteristics of a sitting position that modern people spend a large amount of time in, and can be easily applied to existing chairs. Both algorithms installed in the system detected the center of gravity of the seated person and displayed positional changes that occurred based on the intensity of the postural changes when moving; thus, simultaneous determination of posture and impulsive behavior was possible. To evaluate the system performance, a posture determination evaluation was conducted, along with distraction estimation according to the rate of changes in posture that occur in everyday life. In addition, to evaluate performance in daily life, a movie-watching scenario was set up, and the distracted-limit estimation and concentration indices according to the rate of changes in posture were comparatively evaluated by reviewing a video of the subjects. The results of the posture determination performance evaluation through 100 posture repetitions on 10 subjects showed a high detection performance of 99.04%. The Pearson's correlation coefficient results showed a high correlation coefficient (inverse) of r = -0.975076 and a P-VALUE = 1.654 × 10 - 6 . This experiment objectively confirmed the correlation between the DLE Index (based on postural change) and the CI Index (based on EEG).
Patients with coronavirus disease 2019 (COVID-19) can unknowingly spread the virus to several people during the early subclinical period.
We evaluated the viral dynamics in various body fluid ...specimens, such as nasopharyngeal swab, oropharyngeal swab, saliva, sputum, and urine specimens, of two patients with COVID-19 from hospital day 1 to 9. Additional samples of the saliva were taken at 1 hour, 2 hours, and 4 hours after using a chlorhexidine mouthwash. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load was determined by real-time reverse transcriptase polymerase chain reaction (rRT-PCR).
SARS-CoV-2 was detected from all the five specimens of both patients by rRT-PCR. The viral load was the highest in the nasopharynx (patient 1 = 8.41 log
copies/mL; patient 2 = 7.49 log
copies/mL), but it was also remarkably high in the saliva (patient 1 = 6.63 log
copies/mL; patient 2 = 7.10 log
copies/mL). SARS-CoV-2 was detected up to hospital day 6 (illness day 9 for patient 2) from the saliva of both patients. The viral load in the saliva decreased transiently for 2 hours after using the chlorhexidine mouthwash.
SARS-CoV-2 viral load was consistently high in the saliva; it was relatively higher than that in the oropharynx during the early stage of COVID-19. Chlorhexidine mouthwash was effective in reducing the SARS-CoV-2 viral load in the saliva for a short-term period.
We report the synthesis of a new conjugated polymer composed of isoindigo (IID) and 2,3-bisthiophenyl-2-ylthiophene acrylonitrile (CNTVT) subunits for high-performance n-type organic field-effect ...transistors (OFETs). To realize high electron mobility for the IID-based conjugated polymer, an electron-withdrawing nitrile group is incorporated into the vinylene unit, thereby shifting the energy of the lowest unoccupied molecular orbital for efficient electron injection from Au electrodes without disrupting the backbone planarity. Uniaxially aligned IID24–CNTVT-conjugated polymer films for efficient intramolecular charge transport are achieved by off-center spin-coating from preaggregated solutions. To obtain its stable preaggregation in solution, a binary solvent system (a mixture of good and bad solvents) chosen with the assistance of Hansen solubility parameter simulation is used. Through this process, highly aligned IID24–CNTVT films are obtained by off-center spin coating from a solvent mixture of 9:1 dichlorobenzene/2-methoxyethanol as the good and bad solvents, respectively. The properties of the aligned IID24–CNTVT films are characterized with various analytical techniques, including UV–visible absorption spectroscopy, angle-resolved near-edge X-ray absorption fine structure spectroscopy, and grazing-incidence wide-angle X-ray scattering. Top-gate/bottom-contact OFETs with IID24–CNTVT films aligned in the direction of charge transport exhibit a high-electron field-effect mobility of 0.83 ± 0.13 cm2/V·s.
Problem
Chorioamnionitis is caused by a bacterial infection that ascends from the vagina and can cause adverse pregnancy outcomes (APOs). Fusobacterium nucleatum (F. nucleatum) is a periodontal ...pathogen associated with the occurrence of APOs. In this study, we evaluated whether receptor‐interacting protein kinase 2 (Ripk2), an adaptor protein of the cytosolic receptors nucleotide‐binding oligomerization domain (NOD)1 and NOD2, in macrophages and human decidual stromal cells (hDSCs) contributes to immune responses against F. nucleatum.
Method of Study
Bone marrow‐derived macrophages (BMDMs) isolated from wild‐type (WT) and Ripk2‐deficient mice and hDSCs were cultured with F. nucleatum (MOI 1, 10, 100). BMDMs and hDSCs were assessed using enzyme‐linked immunosorbent assay, Western blot analysis, real‐time PCR, and nitrite assay.
Results
Fusobacterium nucleatum‐induced production of IL‐6, but not of TNF‐α and IL‐10, was lower in Ripk2‐deficient BMDMs than in WT cells. Western blotting revealed a decrease in F. nucleatum‐induced p65 phosphorylation in Ripk2‐deficient macrophages, whereas mitogen‐activated protein kinases activation was comparable between WT and Ripk2‐deficient cells. The production of nitric oxide (NO) in response to F. nucleatum and the gene and protein expression of inducible NO synthase was impaired in Ripk2‐deficient BMDMs. In hDSCs, F. nucleatum upregulated the gene and protein expression of NOD1, NOD2, and Ripk2 in a time‐dependent manner. F. nucleatum also increased the production of IL‐6, CXCL8, and CCL2, whereas this production was decreased by the Ripk2 inhibitors SB203580 and PP2.
Conclusions
In conclusion, Ripk2 signaling appears to contribute to the F. nucleatum‐induced immune response and can be a preventive and therapeutic target against APOs.
Social distancing has been adopted as one of basic protective measures against coronavirus disease 2019 (COVID-19). During 2019-2020 season, influenza epidemic period was exceptionally short and ...epidemic peak was low in comparison with previous seasons in Korea. Influenza epidemic pattern was bimodal in 2016-2017 and 2018-2019 seasons, however, influenza viruses have rarely been circulating in spring, 2020 in Korea. Although multiple factors could affect the size of influenza epidemic, extensive application of nonpharmaceutical interventions including mask wearing and social distancing in response to COVID-19 seems to be a major factor of reduced influenza epidemic. Social distancing measures with high feasibility and high acceptability should be implemented even if severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are developed in the future. Establishment of guideline for workplace social distancing is needed and it would contribute to reduce disease burden of influenza, especially in vaccine mismatch year.
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