Altered glutathione homeostasis in heart augments cardiac lipotoxicity associated with diet-induced obesity in mice

Obesity-related cardiac lipid accumulation is associated with increased myocardial oxidative stress. The role of the antioxidant glutathione in cardiac lipotoxicity is unclear. Cystathionine β-synthase (Cbs) catalyzes the first step in the trans-sulfuration of homocysteine to cysteine, which is estimated to provide ～50% of cysteine for hepatic glutathione biosynthesis. As cardiac glutathione is a reflection of the liver glutathione pool, we hypothesize that mice heterozygous for targeted disruption of Cbs (Cbs(+/-)) are more susceptible to obesity-related cardiolipotoxicity because of impaired liver glutathione synthesis. Cbs(+/+) and Cbs(+/-) mice were fed a high fat diet (60% energy) from weaning for 13 weeks to induce obesity and had similar increases in body weight and body fat. This was accompanied by increased hepatic triglyceride but no differences in hepatic glutathione levels compared with mice fed chow. However, Cbs(+/-) mice with diet-induced obesity had greater glucose intolerance and lower total and reduced glutathione levels in the heart, accompanied by lower plasma cysteine levels compared with Cbs(+/+) mice. Higher triglyceride concentrations, increased oxidative stress, and increased markers of apoptosis were also observed in heart from Cbs(+/-) mice with diet-induced obesity compared with Cbs(+/+) mice. This study suggests a novel role for Cbs in maintaining the cardiac glutathione pool and protecting against cardiac lipid accumulation and oxidative stress during diet-induced obesity in mice.     

Composition and variability of biofouling organisms in seawater reverse osmosis desalination plants

Seawater reverse osmosis (SWRO) membrane biofouling remains a common challenge in the desalination industry, but the marine bacterial community that causes membrane fouling is poorly understood. Microbial communities at different stages of treatment processes (intake, cartridge filtration, and SWRO) of a desalination pilot plant were examined by both culture-based and culture-independent approaches. Bacterial isolates were identified to match the genera Shewanella, Alteromonas, Vibrio, and Cellulophaga based on 16S rRNA gene sequencing analysis. The 16S rRNA gene clone library of the SWRO membrane biofilm showed that a filamentous bacterium, Leucothrix mucor, which belongs to the gammaproteobacteria, accounted for nearly 30% of the clone library, while the rest of the microorganisms (61.2% of the total clones) were related to the alphaproteobacteria. 16S rRNA gene terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that bacteria colonizing the SWRO membrane represented a subportion of microbes in the source seawater; however, they were quite different from those colonizing the cartridge filter. The examination of five SWRO membranes from desalination plants located in different parts of the world showed that although the bacterial communities from the membranes were not identical to each other, some dominant bacteria were commonly observed. In contrast, bacterial communities in source seawater were significantly different based on location and season. Microbial profiles from 14 cartridge filters collected from different plants also revealed spatial trends.     

LncRNA OIP5-AS1 regulates radioresistance by targeting DYRK1A through miR-369-3p in colorectal cancer cells

Object

This study aimed to investigate the role of lncRNA OIP5-AS1 in regulating radioresistance of colorectal cancer (CRC) cells.

一种能表现水稻基因组DNA分化特征的重复DNA顺序

用ＤＮＡ 复性动力学方法克隆到一个水稻中度重复顺序。Ｓｏｕｔｈｅｒｎ 杂交、限制性内切酶分析及序列分析资料表明,该重复顺序在水稻基因组中具有串联重复和散布状态两种存在方式。以该ＤＮＡ 片段作探针,用Ｓｏｕｔｈｅｒｎ 杂交方法分析了多种野生稻种和栽培稻品种的基因组分化特征。某些限制性内切酶消化过的水稻ＤＮＡ,其图谱呈现出多达４０ 条以上的杂交带,包括强杂交带和弱杂交带两种类型。重复实验结果证明,强杂交带表现为ＢＢＣＣ染色体组型特异而弱带则在栽培稻各品种间显示出丰富的多态性,表明该重复顺序片段在水稻理论研究和育种实践中可能具有重要意义     

珊瑚礁生态脆弱性评价——以泰国思仓岛为例

珊瑚礁生态系统受到环境变化、人类活动等各种因素的严重威胁,保护珊瑚礁生态系统是目前全球海洋生态保护的热点,对珊瑚礁开展定量的生态脆弱性评估能够为保护管理对策的制定提供重要科学依据。本研究选取泰国思仓岛作为研究区域,结合空间分析技术建立了具有通用性的珊瑚礁生态脆弱性评估方法。基于ESA模型构建了珊瑚礁生态脆弱性综合指数和评价指标体系,系统分析了思仓岛珊瑚礁脆弱性的来源、构成,并直观展现了脆弱性的区域空间分布。结果表明:思仓岛研究区东北侧的珊瑚礁生态脆弱性大于西南侧,当地珊瑚礁的关键影响因子分别为驳船排污、港口码头、水体透明度等。根据脆弱性评价的结果,提出了当地珊瑚礁保护与修复的空间分区管理对策。本研究为印度-太平洋区系珊瑚礁生态脆弱性评价提供了可行的示例,也为中国的珊瑚礁可持续管理研究提供了借鉴和参照。     

沙地植被碳氮磷化学计量特征与物种多样性的关系

植被化学计量特征表征植物营养限制.它是否会影响物种多样性需要进一步探究.本研究以宁夏哈巴湖国家级自然保护区沙地油蒿群落和沙柳群落为对象,计算了植被碳(C)、氮(N)、磷(P)含量,分析了植被C、N、P生态化学计量特征对沙地植物群落物种多样性的影响.结果表明: 在流动沙丘和半固定沙丘生境中的沙柳群落,物种多样性Simpson指数与植被C/N值存在显著的负相关关系,而与植被N/P值的相关性不显著;在半固定沙丘和固定沙丘生境中的油蒿群落,物种多样性Shannon指数与N/P值存在显著正相关关系,而与C/N值存在显著负相关关系.结合C、N、P生态化学计量特征与冗余分析可知,油蒿群落和沙柳群落的植被P含量对物种多样性的影响不同,导致两个群落的植被N/P值对物种多样性产生不同的影响.     

圈养大熊猫野化培训期的生境选择特征

大熊猫(Ailuropoda melanoleuca)是我国特有的珍稀物种,也是世界上最濒危的野生动物之一。为了将人工繁育的部分大熊猫个体重引入其历史分布区或复壮野生种群,中国保护大熊猫研究中心从2003年开始进行圈养大熊猫的野外放归工作,通过野化培训以提高圈养大熊猫适应和选择野外环境的能力。对野化培训大熊猫"淘淘"的生境选择研究表明:该野化培训大熊猫幼仔经常活动于新笋密度较大的区域[生境与对照:(2.68±1.14)对(1.58±0.66)],却避开成竹密度过大[(9.91±2.51)对(12.18±4.68)]、竹子较高[(4.57±1.09) m对(4.98±0.66) m]以及枯死竹过多[(2.52±0.86)对(3.39±1.33)]的区域;喜欢活动于离水源[(1.59±0.67)对(2.19±0.87)]和隐蔽场所较近[(5.37±2.14) m对(8.35±7.76)m],以及距离乔木较远[(3.09±0.69) m对(2.70±0.42) m]和郁闭度较低[(1.85±0.57)对(2.10±0.47)]的区域(P < 0.05),新笋密度大小是该栖息地在整个野化培训期间是否被利用的最重要因素。该野化培训大熊猫幼仔保持着与带仔母兽相近的生境选择特征,对竹子环境的选择也与卧龙野生大熊猫相似,野化培训对该大熊猫幼仔产生了积极的作用。野化培训大熊猫幼仔形成的家域和核域面积分别为9.21 hm² 和1.93 hm²,占野化培训圈面积的51.95%和10.89%,其中家域面积仅有卧龙野生大熊猫的1.4%-2.4%,所以在以后的野化培训过程中需要采取增加野化培训圈中环境丰富度等方式,促进野化培训大熊猫形成较大的家域面积。     

寄主植物对棉铃虫越冬蛹抗寒能力的影响

通过对滞育蛹过冷却点的测定 ,初步明确寄主对棉铃虫Helicoverpaarmigera的越冬抗寒性有影响 ,幼虫取食棉花时产生的滞育蛹的过冷却点低于取食玉米的滞育蛹的过冷却点 ,即前者的抗寒能力高于后者 ;但用Bt棉喂养后的棉铃虫滞育蛹抗寒能力下降     

我国蝗虫暴发成灾的现状及其持续控制对策

概述并分析了我国蝗虫暴发成灾的现状及原因 ,认为全球气候变暖和区域性气候异常、人类活动的影响、监测预警技术手段落后、成灾蝗种增多和发生为害类型复杂、蝗虫研究队伍锐减及基础理论与高新技术研究滞后导致了近年来蝗虫的暴发成灾。对此 ,作者从蝗虫灾害的规律性、监测预警高新技术和综合治理技术等方面提出了实现蝗灾可持续控制的对策