EMF基因与植物营养生长

在高等植物中,外源和内源因素共同调控着植物从营养生长到生殖生长的转换。拟南芥EMF1和EMF2基因缺失的突变体不经过任何营养生长,种子萌发后便开花,这说明EMF基因是植物花发育的抑制基因。目前已从水稻、玉米、拟南芥等植物中克隆得到EMF同源基因,但其功能研究大多停留在拟南芥上。研究表明,EMF基因决定着植物营养生长阶段的发育,抑制植物开花。因此,开展EMF基因的分离、克隆和功能研究,有利于阐述植物营养生长过程阶段的抑花机制。对EMF基因的研究进展进行了综述,并提出EMF基因表达调控的闸门模型,以对EMF基因功能的进一步分析提供参考。     

Nd：YAP激光的不同功率和时间组合对亚心形扁藻的影响

采用同一剂量不同功率和时间组合的Nd:YAP激光(波长1 341nm)辐照亚心形扁藻,辐照组分为8W 69 s、10 W 55 s和12 W 46 s三个组合,通过藻细胞生长速率和叶绿素含量测定研究激光对扁藻的影响.实验结果表明,即使同一照射剂量,不同的辐照时间与辐照功率的组合,辐照效果仍不相同,本实验中以辐照时间55 s,辐照功率10 W 为最佳组合.     

含硫多肽类抗生素那西肽的菌种诱变及产量提高

那西肽（Ｎｏｓｉｈｅｐｔｉｄｅ）产生菌Ｓｔｒｅｐｔｏｍｙｃｅｓ ａｃｔｕｏｓｕｓ Ｚ１１,经ＮＴＧ处理和对Ｃｕ＾２＋,Ｍｎ＾２＋耐受选育,获得突变株Ｚ１５,其可耐受Ｃｕ＾２＋为３００μｇ／ｍｌ,耐Ｍｎ＾２＋１０００μｇ／ｍｌ,产生那西肽可达１５００μｇ／ｍｌ是Ｚ１１活力的１．６倍。     

基于GIS和GS的东亚飞蝗卵块空间格局的研究

本文以沿渤海蝗区东亚飞蝗Locusta migratoria manilensis (Meyen) 越冬卵块为研究对象,野外采用450 m和50 m规则栅格取样,包括卵量、植被覆盖度、土壤含水量、含盐量、土壤pH和有机质等,利用地统计学方法,在GIS平台下,分析研究区域内影响蝗虫产卵选择的环境因子、蝗虫卵块的空间异质性及分布格局。结果表明, 植被覆盖度、土壤含盐量和土壤含水量在有卵和无卵的环境中存在极显著的差异,飞蝗产卵时最适宜的植被覆盖度、土壤含水量和盐度范围分别为0～30%、10.1%～20.0%和0.09%～1.99%,且当小环境植被覆盖度>50%、土壤含水量>30%或含盐量>3%时,飞蝗不再选择产卵。蝗虫卵块具有高度空间异质性,其空间自相关范围平均为390 m且呈斑块、聚集分布,蝗虫卵块变异函数曲线为球状模型。利用块段克立格法进行空间局部插值,得到研究区域卵块的空间分布格局图,可较准确地描述飞蝗卵块在研究区域内的空间分布、形状、地理位置及相对位置。研究结果可为地面卵块抽样调查、实时跟踪蝗卵胚胎发育进程、确定蝗灾早期发生点、片防治区域及蝗灾早期遥感预警提供科学依据。     

盐芥叶片响应干旱胁迫的蛋白质组学初步分析

盐芥是新兴起的植物非生物逆境研究模式植物,研究盐芥叶片蛋白质组对于干旱胁迫的响应,以推进对植物干旱耐受机制的认识。该研究应用双向电泳技术分析了干旱胁迫对于盐芥叶片蛋白质组的影响,结果共鉴定了63个干旱胁迫差异表达蛋白,包括丰度上调的31个,新出现的蛋白点14个,丰度下调的15个,消失的蛋白点3个。应用生物质谱分析技术确定了包括硫氧还蛋白,铁蛋白-1和凝集素在内的9个干旱胁迫响应蛋白的身份,对这些干旱胁迫响应蛋白的功能分类分析表明,盐芥的耐旱机制可能涉及自由基清除能力的增强、能量代谢的调整以及光合作用的维持。     

双重荧光染色监测听毛细胞游离钙

豚鼠耳蜗分离外毛细胞经fluo-3和fura-red染色后,用激光扫描共聚焦显微镜监测其胞内游离钙的空间分布和动态变化,以fluo-3/fura-red荧光比值大小指示游离钙浓度的高低。外毛细胞胞内游离钙呈不均匀分布,荧光比值分别为细胞质1.71±0.85,质膜1.61±0.75,表皮板1.47±0.65及胞核1.39±0.66,显示细胞质游离钙浓度最高而胞核游离钙浓度最低。静息状态下连续扫描时荧光比值变化小于0.1,而在受到机械刺激后荧光比值增加幅度达0.3—1.2。实验结果表明,fluo-3和fura-red双发射比例法能更准确反映听毛细胞胞内钙的空间分布和动态变化,第二信使钙可能参与了听毛细胞的机械-电换能过程,研究了换能过程中听毛细胞钙信号的时空模式。     

长链非编码RNA在神经系统发育及神经性疾病中的作用

长链非编码RNA(long non-coding RNA,lncRNA)是一类转录本长度在200至数千个核苷酸序列,且不具有蛋白质编码潜能的非编码RNA。相较于研究较多的微小RNA（microRNA,miRNA）和干扰小RNA（small interfering,siRNA）等非编码小RNA,lncRNA的许多功能仍尚不清楚。但越来越多的研究发现,lncRNA可通过多种方式调控中枢神经系统发育,包括表观遗传组蛋白甲基化、转录辅因子调控、可变剪接调控等途经。而以上途经的异常均与多种人类重大疾病的发生密切相关,例如,阿尔兹海默症（Alzheimer’s disease,AD）、自闭症（autism spectrum disorder,ASD）、精神分裂症（schizophrenia,SZ）等。本文就lncRNA在表观遗传水平、转录水平、转录后水平和翻译水平上调控神经系统发育以及其在人类神经性疾病中的作用进行综述。     

Treatment of H2S using a horizontal biotrickling filter based on biological activated carbon: reactor setup and performance evaluation

Biological treatment is an emerging and prevalent technology for treating off-gases from wastewater treatment plants. The most commonly reported odorous compound in off-gases is hydrogen sulfide (H₂S), which has a very low odor threshold. A self-designed, bench-scale, cross-flow horizontal biotrickling filter (HBF) operated with bacteria immobilized activated carbon (termed biological activated carbon—BAC), was applied for the treatment of H₂S. A mixed culture of sulfide-oxidizing bacteria dominated by Acidithiobacillus thiooxidans acclimated from activated sludge was used as bacterial seed and the biofilm was developed by culturing the bacteria in the presence of carbon pellets in mineral medium. HBF performance was evaluated systematically over 120 days, depending on a series of changing factors including inlet H₂S concentration, gas retention time (GRT), pH of recirculation solution, upset and recovery, sulfate accumulation, pressure drop, gas-liquid ratio, and shock loading. The biotrickling filter system can operate at high efficiency from the first day of operation. At a volumetric loading of 900 m³ m^–3 h^–1 (at 92 ppmv H₂S inlet concentration), the BAC exhibited maximum elimination capacity (113 g H₂S/m^–3 h^–1) and a removal efficiency of 96% was observed. If the inlet concentration was kept at around 20 ppmv, high H₂S removal (over 98%) was achieved at a GRT of 4 s, a value comparable with those currently reported for biotrickling filters. The bacterial population in the acidic biofilter demonstrated capacity for removal of H₂S over a broad pH range (pH 1–7). A preliminary investigation into the different effects of bacterial biodegradation and carbon adsorption on system performance was also conducted. This study shows the HBF to be a feasible and economic alternative to physical and chemical treatments for the removal of H₂S.     

5-Aza-CdR对胶质瘤细胞生长及LRRC4基因异常甲基化的影响

LRRC4是一个新发现的胶质瘤抑瘤基因,它在多种胶质瘤细胞系和胶质瘤组织表达缺失或下调,前期研究结果表明胶质瘤细胞和组织中LRRC4的编码区未发生突变、缺失或重排.为了获得LRRC4作为胶质瘤抑瘤基因的进一步证据,采用去甲基化制剂5-Aza-CdR处理LRRC4表达缺失的SF126和SF767胶质瘤细胞,MSP和RT-PCR检测表明,LRRC4的启动子在表达缺失的SF126和SF767细胞存在完全的甲基化,而5-Aza-CdR能逆转LRRC4启动子的甲基化状态,恢复LRRC4的表达.MTf法测定显示,5-Aza-CdR使SF126和SF767胶质瘤细胞增殖受到明显抑制,并呈时间和剂量的依赖性.同时流式细胞仪检测显示,5-Aza-CdR使SF126和SF767胶质瘤细胞周期阻滞于G0/G1期.因此,5-Aza-CdR能抑制胶质瘤细胞SF126和SF767增殖并干扰其细胞周期,LRRC4启动子异常甲基化足其在胶质瘤细胞中表达缺失的重要机制,5-Aza-CdR能逆转LRRC4基因的甲基化,恢复LRRC4的表达,为LRRC4作为胶质瘤去甲基化治疗的靶标提供了科学依据.     

Perforin and Fas cytolytic pathways coordinately shape the selection and diversity of CD8+-T-cell escape variants of influenza virus

Antigenic variation is a viral strategy exploited to promote survival in the face of the host immune response and represents a major challenge for efficient vaccine development. Influenza viruses are pathogens with high transmissibility and mutation rates, enabling viral escape from immunity induced by prior infection or vaccination. Intense selection from neutralizing antibody drives antigenic changes in the surface glycoproteins, resulting in emergence of new strains able to reinfect hosts immune to previously circulating viruses. CD8+ cytotoxic T cells (CTLs) also provide protective immunity from influenza virus infection and may contribute to the antigenic evolution of influenza viruses. Utilizing mice transgenic for an influenza virus NP366-374 peptide-specific T-cell receptor, we demonstrated that the respiratory tract is a suitable site for generation of escape variants of influenza virus selected by CTL in vivo. In this report the contributions of the perforin and Fas pathways utilized by influenza virus-specific CTLs in viral clearance and selection of CTL escape variants have been evaluated. While transgenic CTLs deficient in either perforin- or Fas-mediated pathways are efficient in initial pulmonary viral control, variant virus emergence was observed in all the mice studied, although the spectrum of viral CTL escape variants selected varied profoundly. Thus, a less-restricted repertoire of escape variants was observed in mice with an intact perforin cytotoxic pathway compared with a limited variant diversity in perforin pathway-deficient mice, although maximal variant diversity was observed in mice having both Fas and perforin pathways intact. We conclude that selection of viral CTL escape variants reflects coordinate action between the tightly controlled perforin/granzyme pathway and the more promiscuous Fas/FasL pathway.