Saitohin Q7R polymorphism is associated with late‐onset Alzheimer's disease susceptibility among caucasian populations: a meta‐analysis

Saitohin (STH) Q7R polymorphism has been reported to influence the individual's susceptibility to Alzheimer's disease (AD); however, conclusions remain controversial. Therefore, we performed this meta‐analysis to explore the association between STH Q7R polymorphism and AD risk. Systematic literature searches were performed in the PubMed, Embase, Cochrane Library and Web of Science for studies published before 31 August 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of the association using a fixed‐ or random‐effects model. Subgroup analyses, Galbraith plot and sensitivity analyses were also performed. All statistical analyses were performed with STATA Version 12.0. A total of 19 case–control studies from 17 publications with 4387 cases and 3972 controls were included in our meta‐analysis. The results showed that the Q7R polymorphism was significantly associated with an increased risk of AD in a recessive model (RR versus QQ+QR, OR = 1.27, 95% CI = 1.01–1.60, P = 0.040). After excluding the four studies not carried out in caucasians, the overall association was unchanged in all comparison models. Further subgroup analyses stratified by the time of AD onset, and the quality of included studies provided statistical evidence of significant increased risk of AD in RR versus QQ+QR model only in late‐onset subjects (OR = 1.56, 95% CI = 1.07–2.26, P = 0.021) and in studies with high quality (OR = 1.37, 95% CI = 1.01–1.86, P = 0.043). This meta‐analysis suggests that the RR genotype in saitohin Q7R polymorphism may be a human‐specific risk factor for AD, especially among late‐onset AD subjects and caucasian populations.     

Host species diversity and post-blood feeding carbohydrate availability enhance survival of females and fecundity in Aedes albopictus (Diptera: Culicidae)

Aedes albopictus mosquito is an opportunistic blood feeder and has a broad host range. The feeding behavior and habits of this mosquito are liable to increase the transmission potential of arboviruses. The survival and fecundity in A. albopictus fed on different hosts and post-blood meal provision of sugar were investigated in a laboratory-reared colony. Adult survival of caged female A. albopictus that were fed on blood of two different hosts (double meal) was higher than the females fed only on one host (single meal) (mean survival: 70.2 ± 9.6 vs. 55.5 ± 5.5%, respectively) when held in the laboratory for 72 h after blood feeding. Mean survival of females provided 10% sucrose solution (in water) after a single or double blood meal was higher (90.5 ± 6.4% and 89.3 ± 6.5%, respectively) than in the respective groups receiving water only following blood feeding (double meal: 49.0 ± 9.6%; single meal: 45.3 ± 10.9%). Females receiving a double meal were more fecund on average (89.0 ± 6.6 eggs) than females provided a single meal (82.3 ± 8.2 eggs).     

Catalytic properties of chloroplast F1-ATPase modified at catalytic or noncatalytic sites by 2-azido adenine nucleotides

When heat-activated F1-ATPase from chloroplasts was repeatedly exposed to Mg2+ and 2-azido-ATP, followed by separation from medium nucleotides and photolysis, a total of two sites per enzyme, both catalytic and noncatalytic, were labeled. In a coupled assay with pyruvate kinase about half the activity was lost when one site per enzyme was modified. However, increased modification resulted in no further loss of activity. In contrast, methanol-sulfite activation of the enzyme showed a loss of most of the catalytic capacity when one site per enzyme was modified. Predominant labeling of either one catalytic or one noncatalytic site caused a loss of most of the activity in either assay. An indication that the enzyme modified at one site retained some catalytic activity was verified by measurement of the [18O]Pi species formed when [gamma-18O]ATP was hydrolyzed by partially derivatized enzyme. With either catalytic or noncatalytic site modification, the distributions of [18O]Pi species formed showed that the modified enzyme had different catalytic characteristics. An interpretation is that with modification by azido nucleotides at either catalytic or noncatalytic sites, capacity for rapid catalysis is largely lost but the remaining sites retain weak modified catalytic properties.     

A strong root-specific expression system for stable transgene expression in bread wheat

Key message

A strong, stable and root-specific expression system was developed from a rice root-specific GLYCINE - RICH PROTEIN 7 promoter for use as an enabling technology for genetic manipulation of wheat root traits.

Abstract

Root systems play an important role in wheat productivity. Genetic manipulation of wheat root traits often requires a root-specific or root-predominant expression system as an essential enabling technology. In this study, we investigated promoters from rice root-specific or root-predominant expressed genes for development of a root expression system in bread wheat. Transient expression analysis using a GREEN FLUORESCENT PROTEIN (GFP) reporter gene driven by rice promoters identified six promoters that were strongly expressed in wheat roots. Extensive organ specificity analysis of three rice promoters in transgenic wheat revealed that the promoter of rice GLYCINE-RICH PROTEIN 7 (OsGRP7) gene conferred a root-specific expression pattern in wheat. Strong GFP fluorescence in the seminal and branch roots of wheat expressing GFP reporter driven by the OsGRP7 promoter was detected in epidermal, cortical and endodermal cells in mature parts of the root. The GFP reporter driven by the promoter of rice METALLOTHIONEIN-LIKE PROTEIN 1 (OsMTL1) gene was mainly expressed in the roots with essentially no expression in the leaf, stem or seed. However, it was also expressed in floral organs including glume, lemma, palea and awn. In contrast, strong expression of rice RCg2 promoter-driven GFP was found in many tissues. The GFP expression driven by these three rice promoters was stable in transgenic wheat plants through three generations (T1–T3) examined. These data suggest that the OsGRP7 promoter can provide a strong, stable and root-specific expression system for use as an enabling technology for genetic manipulation of wheat root traits.

     

Intensified plant N and C pool with more available nitrogen under experimental warming in an alpine meadow ecosystem

Nitrogen (N) availability is projected to increase in a warming climate. But whether the more available N is immobilized by microbes (thus stimulates soil carbon (C) decomposition), or is absorbed by plants (thus intensifies C uptake) remains unknown in the alpine meadow ecosystem. Infrared heaters were used to simulate climate warming with a paired experimental design. Soil ammonification, nitrification, and net mineralization were obtained by in situ incubation in a permafrost region of the Qinghai‐Tibet Plateau (QTP). Available N significantly increased due to the stimulation of net nitrification and mineralization in 0–30 cm soil layer. Microbes immobilized N in the end of growing season in both warming and control plots. The magnitude of immobilized N was lower in the warming plots. The root N concentration significantly reduced, but root N pool intensified due to the significant increase in root biomass in the warming treatment. Our results suggest that a warming‐induced increase in biomass is the major N sink and will continue to stimulate plant growth until plant N saturation, which could sustain the positive warming effect on ecosystem productivity.     

Microtubule and microfilament distribution and tubulin content in the cell cycle of Indian muntjac cells

Using DAPI, rabbit antitubulin antibody, FITC-labeled goat anti-rabbit IgG, and TRITC-phalloidin to stain individual cells, the microspectrophotometric analysis showed that three markers that represent the nucleus, microtubules (MT), and microfilaments (MF), respectively, could be recognized in individual cells without interference. The phase of the cell cycle was determined by DNA content. We found that in Indian muntjac (IM) cells, the amount of tubulin in G2 and M phases was about twice as much as that in G1 phase. In G2 cells, the cytoplasmic microtubule complex (CMTC) became denser than in G1 cells. The cytoplasmic MT extent in basically the same orientation as MF bundles in interphase. The regions where the MT is denser also have a denser MF distribution.     

甘肃、青海花尺蛾亚科新种记述(鳞翅目：尺蛾科)

甘肃、青海花尺蛾亚科新种记述（鳞翅目：尺蛾科）薛大勇（中国科学院动物研究所北京１０００８０）孟锋（甘肃省永登县连城实验林场７３０３３３）本文记述采自青海东北部至甘肃境内祁连山地区的三个花尺蛾亚科新种,模式标本保存在中国科学院动物研究所。１．邻库尺峨Ｋ...     

伤寒沙门菌非编码RNA617的分子鉴定及其对生物膜形成的影响研究

本研究旨在探讨伤寒沙门菌(Salmonella enterica serovar Typhi, S. Typhi)中非编码RNA617(non-coding RNA617,ncRNA617)的分子特性,并研究其对生物膜形成的影响及作用机制。采用Northern blot方法检测ncRNA617的表达,通过cDNA 5’末端快速扩增技术(5’-rapid amplification of cDNA end,5’RACE)和逆转录-聚合酶链式反应(reverse transcriotion-polymerase chain reaction,3’RT-PCR)实验分析ncRNA617可能的转录起始位点和终止位点;构建ncRNA617缺陷菌株、回补菌株和过表达菌株等相关菌株,通过生物膜形成实验,观察ncRNA617对伤寒沙门菌生物膜形成的影响,并用实时荧光定量聚合酶链式反应(quantitative real-time polymerase chain reaction,qPCR)分析生物膜形成相关基因表达水平的变化,综合运用生物信息学方法预测ncRNA617和差异基因的结合区域,初步分析ncRNA617发挥调控作用的机制。结果显示,伤寒沙门菌确有ncRNA617的表达,长度约300 nt,其转录起始位点位于mig-14终止密码子下游967 nt处,终止位点位于t2681起始密码子上游 2 378～2 560 nt处。与野生对照菌株相比,ncRNA617缺陷菌株生物膜形成能力增强(P<0.05),回补菌株的生物膜形成能力恢复至野生菌株水平,过表达菌株的生物膜形成能力有所下降(P<0.05)。qPCR结果表明,ncRNA617可负向调控多个生物膜形成相关基因的转录表达水平(P<0.05)。经生物信息学方法预测发现,ncRNA617与差异基因有不同的结合区域。本研究结果提示,ncRNA617在伤寒沙门菌中存在,其长度约270～452 nt。ncRNA617可能通过靶向结合生物膜形成相关基因下调基因表达,从而负向调控伤寒沙门菌生物膜的生成。     

氰氟虫腙对草地贪夜蛾的毒力与田间防效

【目的】本研究旨在明确氰氟虫腙对草地贪夜蛾Spodoptera frugiperda幼虫的毒力水平和田间防治效果,为科学使用氰氟虫腙防治草地贪夜蛾提供参考依据。【方法】采用饲料混毒法在室内测定了氰氟虫腙与4种常用杀虫剂甲维盐、氯虫苯甲酰胺、虱螨脲和茚虫威对草地贪夜蛾3和6龄幼虫的致死中浓度(LC₅₀)及LC₉₀值,以及LC₉₀浓度的这些杀虫剂对3龄幼虫的致死中时(medium lethal time, LT₅₀)值。采用人工喷雾方法测定了玉米田中22%氰氟虫腙悬浮剂(6.6 g/667 m²)、22%氰氟虫腙悬浮剂(17.6 g/667 m²)、5.7%甲维盐水分散剂(1 g/667 m²)和150 g/L茚虫威悬浮剂(2 g/667 m²)对草地贪夜蛾幼虫的防效。【结果】室内生测结果显示,供试的5种杀虫剂中氰氟虫腙对草地贪夜蛾3和6龄幼虫均具有较高的毒力,其LC₅₀值分别为2.64和4.3...