Fine mapping a QTL for carbon isotope composition in tomato

Carbon isotope composition (delta(13)C) and leaf water-use efficiency vary in concert in C3 plants, making delta(13)C useful as a proxy for plant water-use efficiency. A QTL for delta(13)C was detected in the Solanum pennellii chromosome fragment of IL5-4, an introgression line with S. lycopersicum cv. M82 background. M82 and IL 5-4 were crossed, and RFLP markers in the target region converted to PCR-based markers. Forty-one recombinants with an introgression fragment ranging in length from 1.1 to 11.4 cM were identified by marker assisted selection (MAS) among approximately 2000 F2 plants. A total of 29 markers were mapped within the introgression fragment unique to IL5-4. These markers divided the about 9 cM target region into nine intervals. A dominant QTL for delta(13)C, designated QWUE5.1 that explained 25.6% of the total phenotypic variance was mapped to an interval about 2.2 cM long. Twenty-one plants with a S. pennellii chromosome fragment shortened to a length of 2.0-9.1 cM by a second recombination event were generated by MAS of 1,125 F4 plants. Two near isogenic lines with high delta(13)C (small negative value) and carrying QWUE5.1 on the shortest introgression fragments (about 7.0 cM) were identified. The markers and genetic stocks developed are valuable for cloning the gene underlying QWUE5.1, MAS of QWUE5.1, and fine-mapping genes/QTL located in this region.     

Surface N balances and reactive N loss to the environment from global intensive agricultural production systems for the period 1970-2030

Data for the historical years 1970 and 1995 and the FAO-Agriculture Towards 2030 projection are used to calculate N inputs (N fertilizer, animal manure, biological N fixation and atmospheric deposition) and the N export from the field in harvested crops and grass and grass consumption by grazing animals. In most industrialized countries we see a gradual increase of the overall N recovery of the intensive agricultural production systems over the whole 1970-2030 period. In contrast, low N input systems in many developing countries sustained low crop yields for many years but at the cost of soil fertility by depleting soil nutrient pools. In most developing countries the N recovery will increase in the coming decades by increasing efficiencies of N use in both crop and livestock production systems. The surface balance surplus of N is lost from the agricultural system via different pathways, including NH3 volatilization, denitrification, N2O and NO emissions, and nitrate leaching from the root zone. Global NH3-N emissions from fertilizer and animal manure application and stored manure increased from 18 to 34 Tg·yr-1 between 1970 and 1995, and will further increase to 44 Tg·yr-1 in 2030. Similar developments are seen for N2O-N (2.0 Tg·yr-1 in 1970, 2.7 Tg·yr-1 in 1995 and 3.5 Tg·yr-1 in 2030) and NO-N emissions (1.1 Tg·yr-1 in 1970, 1.5Tg·yr-1 in 1995 and 2.0 Tg·yr-1 in 2030).     

Niche-specific features of the intestinal bacteroidales

By analyzing the genomic sequences of 12 Bacteroidales species, we found that all intestinal species have numerous polysaccharide biosynthesis loci, many with promoters that we demonstrate undergo DNA inversion. This feature is not conserved in the Bacteroidales order as a whole, as oral species do not share these genetic features.     

双源CT冠状动脉血管成像诊断心肌桥的价值探讨

目的：研究双源CT冠状动脉血管成像诊断心肌桥的临床价值。方法：选择260例具有典型心前区不适的患者进行双源CT冠脉血管成像检查,观察其发生部位,测量其长度和深度并进行分析。结果：260例受检患者中,62例共70段存在心肌桥,检出率达20.76%,高于文献报道的检出率18.2%。所有心肌桥均发生于左前降支,其中近段17段（24.4%）,中段43段（61.4%）,远段10段（14.2%）。心肌桥平均长度为15.8±6.4mm,深度为1.4±0.85mm。结论：双源CT冠状动脉血管成像因其便捷无创,不受心率严格限制且价格低廉可作为心肌桥筛查的理想检查手段。     

Combined exposure to cigarette smoke and nontypeable Haemophilus influenzae drives development of a COPD phenotype in mice

Background

Cigarette smoke (CS) is the major etiologic factor of chronic obstructive pulmonary disease (COPD). CS-exposed mice develop emphysema and mild pulmonary inflammation but no airway obstruction, which is also a prominent feature of COPD. Therefore, CS may interact with other factors, particularly respiratory infections, in the pathogenesis of airway remodeling in COPD.

Methods

C57BL/6 mice were exposed to CS for 2 h a day, 5 days a week for 8 weeks. Mice were also exposed to heat-killed non-typeable H. influenzae (HK-NTHi) on days 7 and 21. One day after the last exposure to CS, mice were sacrificed and lung inflammation and mechanics, emphysematous changes, and goblet cell metaplasia were assessed. Mice exposed to CS or HK-NTHi alone or room air served as controls. To determine the susceptibility to viral infections, we also challenged these mice with rhinovirus (RV).

Results

Unlike mice exposed to CS or HK-NTHi alone, animals exposed to CS/HK-NTHi developed emphysema, lung inflammation and goblet cell metaplasia in both large and small airways. CS/HK-NTHi-exposed mice also expressed increased levels of mucin genes and cytokines compared to mice in other groups. CS/HK-NTHi-exposed mice infected with RV demonstrated increased viral persistence, sustained neutrophilia, and further increments in mucin gene and chemokine expression compared to other groups.

Conclusions

These findings indicate that in addition to CS, bacteria may also contribute to development of COPD, particularly changes in airways. Mice exposed to CS/HK-NTHi are also more susceptible to subsequent viral infection than mice exposed to either CS or HK-NTHi alone.     

Adipokines and Obesity Are Associated with Colorectal Polyps in Adult Males: A Cross-Sectional Study

Background

Obesity increases the risk of colon cancer. It is also known that most colorectal cancers develop from adenomatous polyps. However, the effects of obesity and adipokines on colonic polyp formation are unknown.

Methods

To determine if BMI, waist circumference or adipokines are associated with colon polyps in males, 126 asymptomatic men (48–65 yr) were recruited at time of colonoscopy, and anthropometric measures as well as blood were collected. Odds ratios were determined using polytomous logistic regression for polyp number (0 or ≥3) and polyp type (no polyp, hyperplastic polyp, tubular adenoma).

Results

41% of the men in our study were obese (BMI ≥30). The odds of an obese individual having ≥3 polyps was 6.5 (CI: 1.3–33.0) times greater than those of a lean (BMI<25) individual. Additionally, relative to lean individuals, obese individuals were 7.8 (CI: 2.0–30.8) times more likely to have a tubular adenoma than no polyp. As BMI category increased, participants were 2.9 (CI: 1.5–5.4) times more likely to have a tubular adenoma than no polyps. Serum leptin, IP-10 and TNF-α were significantly associated with tubular adenoma presence. Serum leptin and IP-10 were significantly associated with increased likelihood of ≥3 polyps, and TNF-α showed a trend (p = 0.09).

Conclusions

Obese men are more likely to have at least three polyps and adenomas. This cross-sectional study provides evidence that colonoscopy should be recommended for obese, white males.     

根施甜菜碱对镍胁迫下小麦幼苗生长生理的影响

以普通小麦品种‘轮选988’为材料,采用溶液培养法,研究了根施不同浓度甜菜碱(1.0、2.0、3.0、4.0、5.0、10.0、15.0、20.0mmol·L~(-1))对镍(100μmol·L~(-1) NiSO_4)胁迫下小麦根系生长的影响,以及4.0mmol·L~(-1)甜菜碱处理镍胁迫幼苗根系相关抗逆生理生化指标的变化。结果表明:(1)与不施加镍对照相比,镍胁迫下小麦幼苗的根长、株高、鲜重和干重分别显著降低了14.7%、11.7%、15.0%和16.7%。(2)与单独镍胁迫处理相比,小麦幼苗的根长、株高、鲜重和干重均随着根施甜菜碱的浓度逐渐增加且呈先升后降的趋势,并以4.0mmol·L~(-1)外源甜菜碱处理效果较佳。(3)与单独镍胁迫处理相比较,在4.0mmol·L~(-1)外源甜菜碱处理下,小麦幼苗根系超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性分别升高了284.7%、40.3%、82.9%和20.4%,超氧阴离子自由基(O-·2)含量、过氧化氢(H_2O_2)含量和丙二醛(MDA)含量分别显著降低了50.6%、38.4%和40.6%,可溶性糖含量及游离脯氨酸(Pro)含量分别显著降低了19.2%、45.4%,而根系活力大幅上升了358.0%。研究认为,根施适宜浓度外源甜菜碱可显著增强小麦幼苗根系的抗氧化能力,恢复根系活力,从而有效减弱镍胁迫对小麦幼苗生长的伤害。