Trichoderma harzianum strain SQR-T37 and its bio-organic fertilizer could control Rhizoctonia solani damping-off disease in cucumber seedlings mainly by the mycoparasitism

Damping-off disease is caused by Rhizoctonia solani and leads to serious loss in many crops. Biological control is an efficient and environmentally friendly way to prevent damping-off disease. Optical micrographs, scanning electron micrographs, and the determination of hydrolytic enzymes were used to investigate the antagonism of Trichoderma harzianum SQR-T37 (SQR-T37) against R. solani. Experiments were performed in pots to assess the in vivo disease-control efficiency of SQR-T37 and bio-organic fertilizer. The results indicate that the mycoparasitism was the main mechanism accounting for the antagonistic activity of SQR-T37. In one experiment, the population of R. solani was decreased from 10⁶ internal transcribed spacer (ITS) copies per gram soil to 10⁴ ITS copies per gram soil by the presence of the antagonist. In this experiment, 45% of the control efficiency was obtained when 8 g of SQR-T37 hyphae per gram soil was applied. In a second experiment, as much as 81.82% of the control efficiency was obtained when bio-organic fertilizer (SQR-T37 fermented organic fertilizer, BIO) was applied compared to only 27.27% of the control efficiency when only 4 g of SQR-T37 hyphae per gram soil was applied. Twenty days after incubation, the population of T. harzianum was 4.12 × 10⁷ ITS copies per gram soil in the BIO treatment, which was much higher than that in the previous treatment (8.77 × 10⁵ ITS copies per gram soil), where only SQR-T37 was applied. The results indicated that SQR-T37 was a potent antagonist against R. solani in a mycoparasitic way that decreased the population of the pathogen. Applying BIO was more efficient than SQR-T37 application alone because it stabilized the population of the antagonist.     

登革病毒血清型特异单克隆抗体的制备和鉴定

登革病毒 (Dengue virus,DENV) 是全球传播最为广泛的虫媒病毒,由于缺乏快速鉴别感染病毒血清型的诊断技术,导致异型交叉感染引起重症登革出血热病例居高不下。为实现免疫学方法快速鉴别诊断不同血清型DENV感染,本研究采用哺乳动物细胞293T表达并纯化了4种DENV血清型NS1蛋白,免疫小鼠后通过杂交瘤技术制备了针对NS1蛋白的单克隆抗体。利用酶联免疫吸附方法 (Enzyme-linked immunosorbent assay,ELISA)、间接免疫荧光法 (Indirect immunofluorescence assay,IFA)、免疫斑点杂交试验 (Dot blotting) 以及蛋白质免疫印迹试验 (Western blotting) 确认所制备的单克隆抗体能够有效识别天然病毒NS1以及重组NS1蛋白。获得的单克隆抗体包含2株可识别1–4型DENV NS1蛋白的通用型抗体及3株分别针对DENV-1、DENV-2和DENV-4的血清型特异抗体。以所制备的DENV NS1抗体为基础,采用双抗体夹心ELISA可快速鉴别不同血清型DENV。DENV血清型特异单克隆抗体的制备和甄别DENV血清型ELISA方法的建立为快速鉴别感染DENV血清型的临床诊断奠定了基础。     

Activation of STAT3 stimulates AHSP expression in K562 cells

Studies on the chaperone proteinα-hemoglobin stabilizing protein(AHSP)reveal that abundant AHSP in erythroid cells enhance the cells’tolerance to oxidative stress imposed by excessα-hemoglobin in pathological conditions.However,the potential intracellular modulation of AHSP expression itself in response to oxidative stress is still unknown.The present study examined the effect and molecular mechanism of STAT3,an oxidative regulator,on the expression of AHSP.AHSP expression increased in K562 cells upon cytokine IL-6-induced STAT3 activation and decreased in STAT3 knock-down K562 cells.Regulation of AHSP in oxidative circumstance was then examined inα-globin-overloaded K562 cells,and real-time PCR showed strengthened expression of both AHSP and STAT3.ChIP analysis showed binding of STAT3 to AHSP promoter and binding was significantly augmented with IL6 stimulation and uponα-globin overexpression.Dual luciferase reporter assays of the wildtype and mutated SB3 element,an IL-6RE site,in the AHSP promoter in K562 cells highlighted the direct regulatory effect of STAT3 on AHSP gene.Finally,direct binding of STAT3 to SB3 site of AHSP promoter was confirmed with EMSA assays.Our work reveals an adaptive AHSP regulation mediated by the redox-sensitive STAT3 signaling pathway,and provides clues to the therapeutic strategy for AHSP enhancement.     

大熊猫生态系统动态模型稳定性及数值分析

本文主要建立大熊猫与两种竹子共生生态系统三种群的微分方程模型,得到Volterra系统,此生态系统是捕食与被捕食关系．分析了该系统在平衡状态处的稳定性,证明了其全局稳定性．最后,通过有关数据的调控确定大熊猫种群数量范围以及计算出该生态系统在平衡状态处受到标准扰动后的恢复时间．     

细胞因子基因转导对人乳腺癌细胞MHC抗原及细胞膜糖蛋白表达的影响

为探讨细胞因子基因(人IL-2、IL-6)转导对于肿瘤细胞膜MHC抗原及细胞膜糖蛋白表达调控的影响,本文利用脂质体介导的方法,将含人IL-6、IL-2基因的逆转录病毒载体分别导入人乳腺癌细胞系MCF-7细胞中,采用间接免疫荧光染色流式细胞仪测定法,对基因转导的瘤细胞细胞膜糖蛋白及MHC抗原表达进行测定。结果表明经两种基因修饰的MCF-7细胞MHCⅠ型抗原表达均获得增强,此外,基因转导细胞可程度不同地表现出细胞膜多种糖蛋白表达的变化。提示肿瘤细胞膜抗原及糖蛋白表达的改变可能是细胞因子基因转导影响肿瘤细胞免疫原性的重要结构基础。     

The thymic stromal cell line MTSC4 induced thymocyte apoptosis in a non-MHC-restricted manner

Mouse thymic stromal cell line 4 (MTSC4) is one of the stromal cell lines established in our laboratory. While losing the characteristics of epithelial cells, they express some surface markers shared with thymic dendritic cells (TDCs). To further study the biological functions of these cells, we compared the capability of MTSC4 with TDCs in the induction of thymocyte apoptosis, using thymic reaggregation culture system. Apoptosis of thymocytes induced by MTSC4 and TDCs was measured by Annexin V and PI staining and analyzed by flow cytometry. We found that MTSC4 selectively augmented the apoptosis of CD4^ 8^ (DP) thymocytes. This effect was Fas/FasL independent and could not be blocked by antibodies to MHC class I and class II molecules. In addition, MTSC4 enhanced the apoptosis of DP thymocytes from different strains of mice, which implies that MTSC4-induced thymocyte apoptosis is not mediated by the TCR recognition of self peptide/MHC molecules. In contrast to MTSC4, thymocyte apoptosis induced by TDCs was MHC-restricted. Thus, MHC-independent fashion of stromal-DP thymocyte interaction may be one of the ways to induce thymocyte apoptosis in thymus. Our study has also shown that the interaction of MTSC4 stromal cells and thymocytes is required for the induction of thymocyte apoptosis.     

甜菜夜蛾在鲁西南地区越冬问题的初步探讨

通过对甜菜夜蛾Spodopteraexigua越冬蛹过冷却点、各虫态发育起点温度、有效积温测定,结合10年来田间调查及越冬观察试验,表明甜菜夜蛾在鲁西南地区一般年份不能安全越冬,得出了每年初代虫源来于外地的结论,这对甜菜夜蛾预测预报和综合防治有着重要的指导作用。     

双向凝胶电泳-飞行时间质谱技术鉴定小鼠胚泡黏附时子宫内膜nm23-M2／NDPK B的表达

运用双向聚丙烯酰胺凝胶电泳(2DPAGE)分析未交配小鼠子宫内膜和妊娠第五天(D5)小鼠子宫内膜胚泡黏附时植入位点及其旁组织蛋白质组。差异蛋白质组学显示,等电点(isoelectric point,pI)约7．1、分子量(molecular weight,Mw)约18kDa的蛋白质点在D5小鼠子宫内膜特别是植入位点表达上调。对此蛋白质点用基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption／ionization time of flying mass spectrometry,MALDI—TOF—MS)测定其胶内酶解后的肽质量指纹谱(Peptide Mass Fingerprint,PMF),经Mascot：Peptide Mass Fingerprint中SWISS-PROT数据库查询后,鉴定该蛋白质为鼠源性nm23-M2／NDPKB。RT—PCR和免疫组织化学结果也显示D5小鼠子宫内膜nm23-M2／NDPK B mRNA和蛋白表达明显增加。提示nm23-M2／NDPKB参与胚泡着床这一重要生命活动过程。     

Posttranslational regulation of AMPA receptor trafficking and function

In the mammalian central nervous system, the majority of fast excitatory synaptic transmission is mediated by glutamate acting on AMPA-type ionotropic glutamate receptors. The abundance of AMPA receptors at the synapse can be modulated through receptor trafficking, which dynamically regulates many fundamental brain functions, including learning and memory. Reversible posttranslational modifications, including phosphorylation, palmitoylation and ubiquitination of AMPA receptor subunits are important regulatory mechanisms for controlling synaptic AMPA receptor expression and function. In this review, we highlight recent advances in the study of AMPA receptor posttranslational modifications and discuss how these modifications regulate AMPA receptor trafficking and function at synapses.