Seasonal Dynamics of Mobile Carbon Supply in Quercus aquifolioides at the Upper Elevational Limit

Many studies have tried to explain the physiological mechanisms of the alpine treeline phenomenon, but the debate on the alpine treeline formation remains controversial due to opposite results from different studies. The present study explored the carbon-physiology of an alpine shrub species (Quercus aquifolioides) grown at its upper elevational limit compared to lower elevations, to test whether the elevational limit of alpine shrubs (<3 m in height) are determined by carbon limitation or growth limitation. We studied the seasonal variations in non-structural carbohydrate (NSC) and its pool size in Q. aquifolioides grown at 3000 m, 3500 m, and at its elevational limit of 3950 m above sea level (a.s.l.) on Zheduo Mt., SW China. The tissue NSC concentrations along the elevational gradient varied significantly with season, reflecting the season-dependent carbon balance. The NSC levels in tissues were lowest at the beginning of the growing season, indicating that plants used the winter reserve storage for re-growth in the early spring. During the growing season, plants grown at the elevational limit did not show lower NSC concentrations compared to plants at lower elevations, but during the winter season, storage tissues, especially roots, had significantly lower NSC concentrations in plants at the elevational limit compared to lower elevations. The present results suggest the significance of winter reserve in storage tissues, which may determine the winter survival and early-spring re-growth of Q. aquifolioides shrubs at high elevation, leading to the formation of the uppermost distribution limit. This result is consistent with a recent hypothesis for the alpine treeline formation

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Joint analysis of three genome-wide association studies of esophageal squamous cell carcinoma in Chinese populations

We conducted a joint (pooled) analysis of three genome-wide association studies (GWAS) 1-3 of esophageal squamous cell carcinoma (ESCC) in ethnic Chinese (5,337 ESCC cases and 5,787 controls) with 9,654 ESCC cases and 10,058 controls for follow-up. In a logistic regression model adjusted for age, sex, study, and two eigenvectors, two new loci achieved genome-wide significance, marked by rs7447927 at 5q31.2 (per-allele odds ratio (OR) = 0.85, 95% CI 0.82-0.88; P=7.72x10−20) and rs1642764 at 17p13.1 (per-allele OR= 0.88, 95% CI 0.85-0.91; P=3.10x10−13). rs7447927 is a synonymous single nucleotide polymorphism (SNP) in TMEM173 and rs1642764 is an intronic SNP in ATP1B2, near TP53. Furthermore, a locus in the HLA class II region at 6p21.32 (rs35597309) achieved genome-wide significance in the two populations at highest risk for ESSC (OR=1.33, 95% CI 1.22-1.46; P=1.99x10−10). Our joint analysis identified new ESCC susceptibility loci overall as well as a new locus unique to the ESCC high risk Taihang Mountain region

Allergen-induced CD11c + dendritic cell pyroptosis aggravates allergic rhinitis

Abstract Background Pyroptosis is crucial for controlling various immune cells. However, the role of allergen-induced CD11c + dendritic cell (DC) pyroptosis in allergic rhinitis (AR) remains unclear. Methods Mice were grouped into the control group, AR group and necrosulfonamide-treated AR group (AR + NSA group). The allergic symptom scores, OVA-sIgE titres, serum IL-1β/IL-18 levels, histopathological characteristics and T-helper cell-related cytokines were evaluated. CD11c/GSDMD-N-positive cells were examined by immunofluorescence analysis. Murine CD11c + bone marrow-derived DCs (BMDCs) were induced in vitro, stimulated with OVA/HDM, treated with necrosulfonamide (NSA), and further cocultured with lymphocytes to assess BMDC function. An adoptive transfer murine model was used to study the role of BMDC pyroptosis in allergic rhinitis. Results Inhibiting GSDMD-N-mediated pyroptosis markedly protected against Th1/Th2/Th17 imbalance and alleviated inflammatory responses in the AR model. GSDMD-N was mainly coexpressed with CD11c (a DC marker) in AR mice. In vitro, OVA/HDM stimulation increased pyroptotic morphological abnormalities and increased the expression of pyroptosis-related proteins in a dose-dependent manner; moreover, inhibiting pyroptosis significantly decreased pyroptotic morphology and NLRP3, C-Caspase1 and GSDMD-N expression. In addition, OVA-induced BMDC pyroptosis affected CD4 + T-cell differentiation and related cytokine levels, leading to Th1/Th2/Th17 cell imbalance. However, the Th1/Th2/Th17 cell immune imbalance was significantly reversed by NSA. Adoptive transfer of OVA-loaded BMDCs promoted allergic inflammation, while the administration of NSA to OVA-loaded BMDCs significantly reduced AR inflammation. Conclusion Allergen-induced dendritic cell pyroptosis promotes the development of allergic rhinitis through GSDMD-N-mediated pyroptosis, which provides a clue to allergic disease interventions. Video Abstrac

Mean concentrations (±1SE, <i>n</i> = 6, % d.m.) of nonstructural carbohydrates (left panels), soluble sugars (middle panels), and starch (right panels) in relation to sampling time for tissues of <i>Quercus aquifoliodes</i> shrubs grown at 3000 m, 3500 m, and 3950 m a.s.l. on the Mt. Zheduo, SW China.

<p>Symbols: • (red) = 3000 m a.s.l.; ▪ (yellow) = 3500 m a.s.l.; Δ (black) = 3950 m a.s.l.</p

Concentration ratios of total soluble sugars to starch (RSS) in tissues of <i>Quercus aquifolioides</i> shrubs grown at elevations of 3000 m, 3500 m, and 3950 m a.s.l. (the elevational limit) during the growing season (May–September) and the dormant season (October–April).

<p>Note (1) Increment (%) was defined as the increment percent of ratio at higher elevation compared to that at 3000 m a.s.l., and (2) ratios were calculated using data shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034213#pone-0034213-g002" target="_blank">Figure 2</a>.</p

Mean concentrations (calculated using pooled data across sampling dates; <i>n</i> = 6) of soluble sugars (dark gray), starch (white), and non-structural carbohydrates (NSC = soluble sugars+starch) in tissues of <i>Quercus aquifolioides</i> plants grown at 3000, 3500, and 3950 m a.s.l. on a SE-facing slope of Mt. Zheduo, Sichuan, SW China.

<p>Different letters indicate statistically significant differences (<i>p</i><0.05) in NSC concentration among elevations. Standard error bars (+1SE) are given for NSC only.</p

Mean biomass and pool size of non-structural carbohydrates (NSC) at individual and stand level (both <i>n</i> = 6) of <i>Quercus aquifolioides</i> shrubs grown at 3000, 3500, and 3950 m a.s.l. on a SE-facing slope of Mt. Zheduo, SW China.

<p>Different letters indicate statistically significant differences (<i>p</i><0.05) in biomass or NSC pool size among elevations. Standard errors bars (+1SE) are given for the total above- or below-ground biomass or the total above- or below-ground NSC pool size.</p

Mean concentrations of soluble sugars (dark gray), starch (white), and non-structural carbohydrates (NSC = soluble sugars+starch) in tissues of <i>Quercus aquifolioides</i> grown at 3000 m, 3500 m, and 3950 m a.s.l. during the growing season (May–September) and the dormant season (October–April), calculated using data measured across an one-year cycle from May 2008 to April 2009.

<p>Statistical differences in means among elevations within each tissue category and season were tested by t-paired comparison. Different letters indicate statistically significant differences (p<0.05) in NSC among elevations. Standard error bars (+1SE) are given for NSC only.</p