DNA Methylation of the Autonomous Pathway Is Associated with Flowering Time Variations in Arabidopsis thaliana.

Plant flowering time is affected by endogenous and exogenous factors, but its variation patterns among different populations of a species has not been fully established. In this study, 27 Arabidopsis thaliana accessions were used to investigate the relationship between autonomous pathway gene methylation, gene expression and flowering time variation. DNA methylation analysis, RT-qPCR and transgenic verification showed that variation in the flowering time among the Arabidopsis populations ranged from 19 to 55 days and was significantly correlated with methylation of the coding regions of six upstream genes in the autonomous pathway, FLOWERING LOCUS VE (FVE), FLOWERING LOCUS Y (FY), FLOWERING LOCUS D (FLD), PEPPER (PEP), HISTONE DEACETYLASE 5 (HAD5) and Pre-mRNA Processing Protein 39-1 (PRP39-1), as well as their relative expression levels. The expression of FVE and FVE(CS) was modified separately through degenerate codon substitution of cytosine and led to earlier flowering of transgenic plants by 8 days and 25 days, respectively. An accurate determination of methylated sites in FVE and FVE(CS) among those transgenic plants and the recipient Col-0 verified the close relationship between the number of methylation sites, expression and flowering time. Our findings suggest that the methylation variation of these six key upstream transcription factors was associated with the gene expression level of the autonomous pathway and flowering time in Arabidopsis. The FVE(CS) and FVE genes in transgenic plants tended to be hypermethylated, which could be a protective mechanism for plants. However, modification of gene sequences through degenerate codon substitution to reduce cytosine can avoid hypermethylated transferred genes in transgenic plants. It may be possible to partially regulate the flowering of plants by modified trans-epigenetic technology.

Climate-dependent variation in cold tolerance of weedy rice and rice mediated by OsICE1 promoter methylation.

The mechanisms by which weedy rice (Oryza sativa f. spontanea) has adapted to endure low-temperature stress in northern latitudes remain unresolved. In this study, we assessed cold tolerance of 100 rice varieties and 100 co-occurring weedy rice populations, which were sampled across a broad range of climates in China. A parallel pattern of latitude-dependent variation in cold tolerance was detected in cultivated rice and weedy rice. At the molecular level, differential cold tolerance was strongly correlated with relative expression levels of CBF cold response pathway genes and with methylation levels in the promoter region of OsICE1, a regulator of this pathway. Among all methylated cytosine sites of the OsICE1 promoter, levels of CHG and CHH methylation were found to be significantly correlated with cold tolerance among accessions. Furthermore, within many of the collection locales, weedy rice shared identical or near-identical OsICE1 methylation patterns with co-occurring cultivated rice. These findings provide new insights on the possible roles that methylation variation in the OsICE1 promoter may play in cold tolerance, and they suggest that weedy rice can rapidly acquire cold tolerance via methylation patterns that are shared with co-occurring rice cultivars.

Polyploidization-driven differentiation of freezing tolerance in Solidago canadensis.

Solidago canadensis, originating from the temperate region of North America, has expanded southward to subtropical regions through polyploidization. Here we investigated whether freezing tolerance of S. canadensis was weakened during expansion. Measurement of the temperature causing 50% ruptured cells (LT50 ) in 35 S. canadensis populations revealed ploidy-related differentiation in freezing tolerance. Freezing tolerance was found to decrease with increasing ploidy. The polyploid populations of S. canadensis had lower ScICE1 gene expression levels but more ScICE1 gene copies than the diploids. Furthermore, more DNA methylation sites in the ScICE1 gene promoter were detected in the polyploids than in the diploids. The results suggest that promoter methylation represses the expression of multi-copy ScICE1 genes, leading to weaker freezing tolerance in polyploid S. canadensis compared to the diploids. The study provides empirical evidence that DNA methylation regulates expression of the gene copies and supports polyploidization-driven adaptation to new environments.

Variation in ICE1 Methylation Primarily Determines Phenotypic Variation in Freezing Tolerance in Arabidopsis thaliana.

Cold stress is a major abiotic factor plants face during their life cycle. Although plants often exhibit phenotypic variation in cold tolerance, the underlying mechanism remains poorly understood. In the present study, the 50% lethal temperature (LT50) values of 37 Arabidopsis thaliana accessions at latitudes from 15° to 58° ranged from -13.2°C to -4.9°C and were closely correlated with the cold climates of the collection sites. According to a methylation analysis of all C-repeat (CRT)-binding factor (CBF) pathway genes, the coding and promoter regions of AtICE1, a regulator of CBF genes, exhibited the greatest variability in methylation levels among the accessions and included 5-122 methylated cytosine residues. In contrast, unmethylated or only slightly methylated genes in the CBF pathway showed little variation among the accessions. According to a gene expression analysis of four selected A. thaliana populations with distinct methylation patterns, except for the down-regulated gene AtCBF2, the expression levels of all members of the CBF pathway were negatively correlated with AtICE1 gene methylation levels. Treatment of the four A. thaliana populations with the DNA methylation inhibitory reagent 5-azacytidine resulted in a 30.0-78.3% enhancement of freezing tolerance and decreases in LT50 values of approximately 1.9-3.6°C. Similar effects were observed in drm2 mutants, including 30.0-48.3% increases in freezing tolerance and decreases in LT50 values of approximately 0.7-3.4°C. Thus, the AtICE1 methylation-regulated transcription of CBF pathway genes is responsible for the phenotypic variation in the freezing tolerance observed in A. thaliana.

Correlation between the cell population in the automated hematology analyzer high-fluorescence region and atypical lymphocyte flags.

INTRODUCTION: During routine blood measurements using an automated hematology analyzer, two easily confused types of suspect flags related to lymphocytes often appear: atypical and immature lymphocytes. The aim of this study was to investigate the correlation of high fluorescence cell (HFC) parameter and lymphocyte flags determined from an automated hematology analyzer. METHODS: A total of 93 patients affected by various pathologic conditions (viral infection, immunological disease, oncological disease and tumor) were divided into an "atypical lymphocytes" group ("atypical" for short), an "immature lymphocytes/blasts" flag group (abnormal), a mixed-flag group that includes "atypical lymphocytes" (mixed), and a non-flag group (non-flag). RESULTS: The numbers of HFCs in the atypical, abnormal, mixed, and non-flag groups were 1.8% (0.9%-5.5%), 0.7% (0.1%-5.0%), 2.3% (1.2%-5.0%), and 0.8% (0.7%-1.2%), respectively. The HFCs of "atypical" appeared as a separate cluster with clear boundaries. The HFCs of "abnormal" as an unclear boundaries, and it was difficult to accurately distinguish between the HFCs from the immature lymphocytes and the normal lymphocytes. The lower limit of HFC when the atypical lymphocyte flag appeared was 0.04 × 109 /L. The number of HFCs was similar to atypical lymphocytes detected by microscopy and CD19+ CD20- CD27++ cells by flow cytometry at 78% and 76%, respectively. The number of HFCs detected in "atypical" and CD19+ CD20- CD27++ cells showed good consistency (r = .715), whereas the consistency was poorest for "abnormal" (r = .176). CONCLUSION: It demonstrates that HFCs reflects atypical lymphocytes better than immature lymphocytes/blasts.

Error-prone PCR mutation of Ls-EPSPS gene from Liriope spicata conferring to its enhanced glyphosate-resistance.

Liriope spicata (Thunb.) Lour has a unique LsEPSPS structure contributing to the highest-ever-recognized natural glyphosate tolerance. The transformed LsEPSPS confers increased glyphosate resistance to E. coli and A. thaliana. However, the increased glyphosate-resistance level is not high enough to be of commercial value. Therefore, LsEPSPS was subjected to error-prone PCR to screen mutant EPSPS genes capable of endowing higher resistance levels. A mutant designated as ELs-EPSPS having five mutated amino acids (37Val, 67Asn, 277Ser, 351Gly and 422Gly) was selected for its ability to confer improved resistance to glyphosate. Expression of ELs-EPSPS in recombinant E. coli BL21 (DE3) strains enhanced resistance to glyphosate in comparison to both the LsEPSPS-transformed and -untransformed controls. Furthermore, transgenic ELs-EPSPS A. thaliana was about 5.4 fold and 2-fold resistance to glyphosate compared with the wild-type and the Ls-EPSPS-transgenic plants, respectively. Therefore, the mutated ELs-EPSPS gene has potential value for has potential for the development of glyphosate-resistant crops.

Multiple mechanism confers natural tolerance of three lilyturf species to glyphosate.

MAIN CONCLUSION: A combination of unique EPSPS structure and increased gene copy number and expression contribute to natural glyphosate tolerance in three lilyturf species. A few plants are naturally tolerant to glyphosate, the most widely used non-selective herbicide worldwide. Here, the basis for natural tolerance to glyphosate in three lilyturf species, Ophiopogon japonicus (OJ), Liriope spicata (LS), and Liriope platyphylla (LP), is characterized. These species tolerate glyphosate at about five times the commercially recommended field dose. They share three unique amino acids in their 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) that affect glyphosate binding. These correspond to Asp71Met, Ala112Ile, and Val201Met amino acid variations compared to 231 other published plant EPSPS amino acid sequences. There was also a common deletion at 91 of a highly conserved glutamic acid. Glyphosate-treated lilyturf plants accumulated little shikimic acid but had significantly higher levels of EPSPS mRNA than initially expressed in the control. The IC50 of LsEPSPS was 14.0 µM compared to the 5.1 µM of Arabidopsis thaliana. The higher K m and K i values of LsEPSPS kinetics showed that LsEPSPS had lower substrate binding affinity to glyphosate. Overexpression of LsEPSPS in the recombinant E. coli BL21 (DE3) strain enhanced its tolerance to glyphosate. Both OJ and LS had two copies of the EPSPS gene, while LP had three copies. Therefore, a combination of unique EPSPS structure and increased gene copy number and expression contribute to natural glyphosate tolerance in the three lilyturf species.

Cloning, expression and characterization of novel hyaluronan lyases Vhylzx1 and Vhylzx2 from Vibrio sp. ZG1.

Hyaluronidases are a class of enzymes that can degrade hyaluronic acid and have a wide range of applications in the medical field. In this study, the marine bacterium Vibrio sp. ZG1, which can degrade HA, was isolated, leading to the discovery of two novel hyaluronan lyases, Vhylzx1 and Vhylzx2, through genome sequencing and bioinformatic analysis. These lyases belong to the polysaccharide lyase-8 family. Vhylzx1 and Vhylzx2 specifically degrade HA, with highest activity at 35 °C, pH 5.7 and 50 °C, pH 7.1. Vhylzx1 and Vhylzx2 are endo-type enzymes that can fully degrade HA into unsaturated disaccharides. Sequence homology assessment and site-directed mutagenesis revealed that the catalytic residues of Vhylzx1 are Asn231, His281, and Tyr290, and that the catalytic residues of Vhylzx2 are Asn227, His277, and Tyr286. Moreover, this study used consensus sequences to enhance the specific activity of Vhylzx2 mutants. Notably, the mutants V564I, N742D, L619F, and D658G increases the specific activity by 2.4, 2.2, 1.3, and 1.2-fold. These characteristics are useful for further basic research and applications, and have a promising application in the preparation of biologically active hyaluronic acid oligosaccharides.

[Variation of irradiance in the arctic pole during the summer].

The variation of irradiance affect the melting rate of the sea ice in the arctic pole, and the research on it is an important component of the global climate change research. The present research was based on the spectrum data collected during the 4th scientific research on the arctic of China in 2010, analyzed the variation of irradiance in the arctic pole during the summer and discussed the reasons for the change. This research shows that many factors lead to the change, among which the weather and the solar elevation angle affect the irradiance directly. The weather factors determine the amount of solar radiation that reached the ground after the absorption and attenuation of the clouds; In high-latitude areas, there is a low solar elevation angle and the attenuation of solar radiation was obvious. Our research shows that the spectrum at shorter wavelength is more sensitive to the changes in altitude of the sun, while the impact of weather on the irradiance increases with wavelength. Moreover, moisture content in the atmosphere also affects the solar radiation reaching the ground and the its impact is in a particular band but not for the entire spectrum range.

[Spectral features analysis of sea ice in the Arctic Ocean].

Sea ice in the Arctic Ocean plays an important role in the global climate change, and its quick change and impact are the scientists' focus all over the world. The spectra of different kinds of sea ice were measured with portable ASD FieldSpec 3 spectrometer during the long-term ice station of the 4th Chinese national Arctic Expedition in 2010, and the spectral features were analyzed systematically. The results indicated that the reflectance of sea ice covered by snow is the highest one, naked sea ice the second, and melted sea ice the lowest. Peak and valley characteristics of spectrum curves of sea ice covered by thick snow, thin snow, wet snow and snow crystal are very significant, and the reflectance basically decreases with the wavelength increasing. The rules of reflectance change with wavelength of natural sea ice, white ice and blue ice are basically same, the reflectance of them is medium, and that of grey ice is far lower than natural sea ice, white ice and blue ice. It is very significant for scientific research to analyze the spectral features of sea ice in the Arctic Ocean and to implement the quantitative remote sensing of sea ice, and to further analyze its response to the global warming.

Impacts of Built Environment on Risk of Women's Lung Cancer: A Case Study of China.

Built environment factors such as air pollution are associated with the risk of respiratory disease, but few studies have carried out profound investigation. We aimed to evaluate the association between the built environment and Chinese women's lung cancer incidence data from the China Cancer Registry Annual Report 2017, which covered 345,711,600 people and 449 qualified cancer registries in mainland China. The air quality indicator (PM2.5) and other built environment data are obtained from the China Statistical Yearbook and other official approved materials. An exploratory regression tool is applied by using Chinese women's lung cancer incidence data (Segi population) as the dependent variable, PM2.5 index and other built environment factors as the independent variables. An apparent clustering region with a high incidence of women's lung cancer was discovered, including regions surrounding Bohai bay and the three Chinese northeastern provinces, Heilongjiang, Liaoning and Inner Mongolia. Besides air quality, built environment factors were found to have a weak but clear impact on lung cancer incidence. Land-use intensity and the greening coverage ratio were positive, and the urbanization rate and population density were negatively correlated with lung cancer incidence. The role of green spaces in Chinese women's lung cancer incidence has not been proven.

Bilateral occurrence of sperm granulomas in the left spermatic cord and on the right epididymis: A case report.

BACKGROUND: Sperm granuloma is a rare disease in clinical andrology and its incidence is still unclear worldwide. According to the existing literature, sperm granuloma often occurs unilaterally. Clinical and ultrasound features are similar to epididymal tuberculosis, chronic epididymitis and other diseases. Sperm granuloma is usually diagnosed based on postoperative histopathological and immunohistochemical examination. CASE SUMMARY: A 46-year-old man was admitted to the hospital due to the presence of a left scrotal mass for 3 mo and aggravation of pain for 1 wk. The lesions at both sites were surgically resected. Postoperative pathological examination showed that the left spermatic cord mass and the right epididymal mass were consistent with sperm granuloma. The sperm granulomas then recurred 3 mo after surgery. There is little change in the local mass so far. CONCLUSION: The case report is helpful for our understanding of this disease. In clinical diagnosis, it should be distinguished from epididymal tuberculosis, chronic epididymitis and other diseases. Color Doppler ultrasound can be used as a preferred examination method but postoperative pathological examination is still needed for diagnosis.

Risk factors for new-onset diabetes mellitus after kidney transplantation: A systematic review and meta-analysis.

AIMS/INTRODUCTION: To systematically review the risk factors for new-onset diabetes mellitus after kidney transplantation, and to provide a theoretical basis for the prevention and management of new-onset diabetes mellitus after kidney transplantation. MATERIALS AND METHODS: We searched PubMed, Web of Science, Embase, the Cochrane Library databases and other databases for case-control studies related to risk factors for new-onset diabetes mellitus after kidney transplantation published between January 2005 and July 2019. A meta-analysis of data on risk factors for new-onset diabetes mellitus after kidney transplantation from the included studies was carried out. A narrative review of risk factors for new-onset diabetes mellitus after kidney transplantation was also carried out. RESULTS: A total of 24 case-control studies were included in the meta-analysis, with a total of 7,140 patients. There were 1,598 patients with new-onset diabetes mellitus after kidney transplantation, and 5,542 patients without new-onset diabetes mellitus after kidney transplantation. The meta-analysis results showed that age, polycystic kidney disease, family history of diabetes, body mass index, acute rejection, tacrolimus use, hepatitis B virus infection, hepatitis C virus infection and hypertension were associated with new-onset diabetes mellitus after kidney transplantation, whereas sex, sirolimus use, cyclosporin A use, steroid use and cytomegalovirus infection were not associated with new-onset diabetes mellitus after kidney transplantation. CONCLUSIONS: Older age, body mass index, family history of diabetes, tacrolimus use, history of hypertension, polycystic kidney disease, acute rejection, hepatitis B virus infection and hepatitis C virus infection are risk factors for new-onset diabetes mellitus after kidney transplantation. Therefore, the clinical implications of these factors warrant attention.

Solitary testicular neurofibromatosis with testicular abscess: a case report.

Solitary neurofibroma of male reproductive system is a very rare benign peripheral nerve tumor. The literature data of 17 cases showed that most of the patients went to see a doctor because of the local painless enlargement of the reproductive system. We report a case of testicular neurofibromatosis diagnosed as enlargement of the scrotum and rupture of pus. After comprehensive consideration, the patients were given radical orchiectomy on the right side. This case report is helpful to the understanding of this rare tumor. Solitary neurofibromatosis of the reproductive system can also cause local infection and collapse, and we need to distinguish it from malignant tumors.

Hepatitis B virus serological screen in a general hospital in Beijing from 2008 to 2018, and challenges to our vaccination policy.

OBJECTIVE: Hepatitis B virus (HBV) has a worldwide distribution and remains a leading public health problem in China. METHOD: Automated chemiluminescence microparticle immunoassay was used to test all five markers of HBV serology in serum samples among 696,048 patients, pregnant women, and normal subjects in Beijing from 2008 to 2018. RESULTS: The overall prevalence of subjects categorized as previous/ occult HBV infection, inactive HBsAg carrier, active HBV infection, HBsAg, HBV susceptible, and immune via vaccination was 29.4%, 4.8%, 1.4%, 6.4%, 33.9% and 30.3%, respectively; men had a significantly higher prevalence of HBV infection than women. The prevalence of HBsAg was around 0.5% in subjects ≤ 10 years of age, increased dramatically to 3.7% in subjects between 11 and 20 years of age, reached the highest level of 7.9% in subjects between 41 and 50 years of age, and finally decreased to 2.8% in subjects ≥ 81 years of age. During the 10 years from 2008 to 2018, the prevalence of HBsAg was stabilized at about 6.0%, and indicators of HBV susceptibility, previous/ occult HBV infection, and immunity via vaccination were not further improved, despite the constant implementation of HBV vaccination since 1992. All four age groups (21 - 30y, 31 - 40y, 41 - 50y and 51 - 60y) of the normal adult population were found to have a significantly lower prevalence of HBsAg and HBV susceptibility but significantly higher prevalence of immunity via vaccination compared with corresponding age groups of the sub-total population. CONCLUSIONS: Although high coverage has been established among infants and young children, their vaccination alone could not reduce HBV infection in the adult Chinese population quickly. Adult populations with more vaccinated individuals are found to have fewer individuals with HBsAg. Vaccination in adults or at least in high-risk adults is an urgent need to decrease horizontal HBV transmission in China.

The degradation of BPA on enhanced heterogeneous photo-Fenton system using EDDS and different nanosized hematite.

Photo-Fenton processes have been widely studied in wastewater treatment. In this research, the degradation of bisphenol A (BPA) was carried out in a new heterogeneous photo-Fenton process. The ethylenediamine-N,N'-disuccinic acid (EDDS) was used as chelating agent in this system with two different kinds of commercially available nanosized hematite (30 nm and 80 nm) addition. The results showed that the present of EDDS could enhance the degradation efficiency. And can be concluded that the degradation efficiency is better in the system with 30 nm hematite. The TEM, XRD, and specific surface area were conducted to understand the different characteristics of the two size hematite. The adsorption experiments of BPA and EDDS on hematite proved that there was little adsorption of BPA while the EDDS was adsorbed much more on hematite, which has confirmed Fe(III) and EDDS can form Fe(III)-EDDS complex. The effects of different parameters including hematite loading, H2O2, and EDDS concentrations on the degradation process were investigated. According to the results, the optimum condition for BPA degradation using 30 nm (0.8 g L-1 hematite, 0.1 mmol L-1 H2O2, and 1.2 mmol L-1 EDDS) and 80 nm (0.6 g L-1 hematite, 0.05 mmol L-1 H2O2, and 1.2 mmol L-1 EDDS) hematite were selected. It was confirmed that the ·OH plays an important role in the oxidation process through attacking the BPA molecule and produce hydroxyl addition derivative. In addition, O2 can react with electron (e-) and holes (h+) produced by iron oxide under UV irradiation to create 1O2, which could work as potential reactive species to oxidize BPA.

Cytomegalovirus antigenemia in patients with autoimmune and non-autoimmune diseases in Beijing: A 10-year single hospital experience.

BACKGROUND: Primary cytomegalovirus (CMV) infection is prevalent worldwide and usually results in latency in immunocompetent populations. Reactivation of latent CMV can cause life-threatening complications in immunocompromised hosts. METHODS: We used the CMV Brite assay to test CMV antigenemia (pp65) in whole blood samples from 22,192 patients with or without autoimmune diseases in Beijing during 2008-2018. RESULTS: The overall prevalence of CMV antigenemia was 19.5% (9.7%, males; 26.0%, females). The prevalence of CMV antigenemia was 35.1%, 58.6% and 11.4% in whole patients with autoimmune diseases, in patients with systemic lupus erythematosus (SLE) and in patients with non-SLE autoimmune diseases, respectively. All patients with non-autoimmune diseases, patients with HIV/AIDS or transplantation were found to have 5.0%, 27% or 14.8%, respectively. Patients≤20 years with SLE had a significantly higher prevalence of CMV antigenemia than did all SLE patients, on average. Patients>51 years with non-SLE autoimmune diseases had a significantly higher prevalence than did all patients with non-SLE autoimmune diseases, on average. The prevalence of CMV antigenemia in patients admitted to intensive-care units (ICUs) were 9.2%, which was significantly higher than that among all patients with non-autoimmune diseases. Patients with SLE had 23.8% of negative conversion of CMV antigenemia, significantly lower than the percentage of patients with non-SLE autoimmune (64.3%) and non-autoimmune (61.0%) diseases. The mean number of days to negative conversion of CMV antigenemia in patients with SLE was 35.3±35.8 days, which was significantly longer than that in patients with non-SLE autoimmune diseases (15.4±11.9 days) and non-autoimmune diseases (13.6±7.7 days). CONCLUSIONS: CMV antigenemia is found more likely in women than in men, more prevalently in patients with SLE than those with HIV/AIDS or transplant recipients, more frequently in patients admitted to ICUs. Patients with SLE had prolonged CMV antigenemia. The role of CMV appears important in SLE.

Publisher Correction: Grassland dynamics in response to climate change and human activities in Xinjiang from 2000 to 2014.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

A spatio-temporal continuous soil moisture dataset over the Tibet Plateau from 2002 to 2015.

Surface soil moisture is a key variable in the exchange of water and energy between the land surface and the atmosphere, and critical to meteorology, hydrology, and ecology. The Tibetan Plateau (TP), known as "The third pole of the world" and "Asia's water towers", exerts huge influences on and sensitive to global climates. In this situation, longer time series of soil moisture can provide sufficient information to understand the role of the TP. This paper presents the first comprehensive dataset (2002-2015) of spatio-temporal continuous soil moisture at 0.25° resolution, based on satellite-based optical (i.e. MODIS) and microwave (ECV) products using a machine learning method named general regression neural network (GRNN). The dataset itself reveals significant information on the soil moisture and its changes over the TP, and can aid to understand the potential driven mechanisms for climate change over the TP.