Comparative mapping of QTLs for Al tolerance in rice and identification of positional Al-induced genes

Aluminum (Al) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an A1 sensitive lowland indica rice variety IR1552 and an Al tolerant upland japonica rice variety Azucena, was used for mapping quantitative trait loci (QTLs) for A1 tolerance. Three QTLs for relative root length (RRL) were detected on chromosome 1, 9, 12, respectively, and I QTL for root length under Al stress is identical on chromosome I after one week and two weeks stress. Comparison of QTLs on chromosome 1 from different studies indicated an identical interval between C86 and RZ801 with gene(s) for Al tolerance. This interval provides an important start point for isolating genes responsible for A1 tolerance and understanding the genetic nature of Al tolerance in rice. Four Al induced ESTs located in this interval were screened by reverse Northern analysis and confirmed by Northern analysis. They would be candidate genes for the QTL.     

河北省不同群体耵聍频率分布

本文在调查河北汉族、满族、回族耵聍性状的基础上计算出上述三个民族的基因频率,并进行三个民族之间、三个民族与外国人之间耵聍干、湿型基因频率的比较。研究结果提示:汉族干型基因频率最高,依次是:汉>回>满。     

Trapping endoplasmic reticulum with amphiphilic AIE-active sensor via specific interaction of ATP-sensitive potassium (KATP)

The current aggregation-induced emission luminogens (AIEgens) sometimes suffer from poor targeting selectivity due to undesirable aggregation in the hydrophilic biosystem with ‘always-on’ fluorescence or unspecific aggregation in the lipophilic organelle with prematurely activated fluorescence. Herein, we report an unprecedented ‘amphiphilic AIEgen’ sensor QM-SO₃-ER based on the AIE building block of quinoline-malononitrile (QM). The introduced hydrophilic sulfonate group can well control the specific solubility in a hydrophilic system with desirable initial ‘fluorescence-off’ state. Moreover, the incorporated p-toluenesulfonamide group plays two roles: enhancing the lipophilic dispersity, and behaving as binding receptor to the adenosine triphosphate (ATP)-sensitive potassium (K_ATP) on the endoplasmic reticulum (ER) membrane to generate the docking assay confinement effect with targetable AIE signal. The amphiphilic AIEgen has for the first time settled down the predicament of unexpected ‘always-on’ fluorescence in the aqueous system and the untargetable aggregation signal in the lipophilic organelle before binding to ER, thus successfully overcoming the bottleneck of AIEgens'' targetability.     

Osteogenic differentiation of mesenchymal stem cells promoted by overexpression of connective tissue growth factor

Objective: Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques. The aim of this study is to investigate the effect of connective tissue growth factor (CTGF) on the proliferation and osteogenic differentiation of the bone marrow mesenchymal stem cells (MSCs). Methods: A CTGF-expressing plasmid (pCTGF) was constructed and transfected into MSCs. Then expressions of bone morphogenesis-related genes, proliferation rate, alkaline phosphatase activity, and mineralization were examined to evaluate the osteogenic potential of the CTGF gene-modified MSCs. Results: Overexpression of CTGF was confirmed in pCTGF-MSCs. pCTGF transfection significantly enhanced the proliferation rates of pCTGF-MSCs (P<0.05). CTGF induced a 7.5-fold increase in cell migration over control (P<0.05). pCTGF transfection enhanced the expression of bone matrix proteins, such as bone sialo-protein, osteocalcin, and collagen type I in MSCs. The levels of alkaline phosphatase (ALP) activities of pCTGF-MSCs at the 1st and 2nd weeks were 4.0- and 3.0-fold higher than those of MSCs cultured in OS-medium, significantly higher than those of mock-MSCs and normal control MSCs (P<0.05). Overexpression of CTGF in MSCs enhanced the capability to form mineralized nodules. Conclusion: Overexpression of CTGF could improve the osteogenic differentiation ability of MSCs, and the CTGF gene-modified MSCs are potential as novel cell resources of bone tissue engineering.     

基因重组对企业发展的影响

随着市场经济的发展,企业的目标已不仅仅是获得满意的利润,还在追求企业的长寿、持续发展。而市场环境的不确定性及高度复杂性等特点又加大了企业持续发展的困难,本文针对这样一种状况,将企业看作生命体,借鉴了生物基因重组的思想,从企业基因重组理论的视角,探讨了企业基因重组对企业发展的影响,并认为企业可以通过基因重组产生企业的差异性和多样性,进而形成了企业难以复制的竞争优势,达到企业的持续发展的目的。     

亲密因子对科研合作网的影响

参照人际关系网络中的亲密因子构造一个科研合作网络演化模型,分别从网络的度分布、点强度分布、平均路径长度以及聚集系数对亲密因子进行分析,发现演化后的科研合作网具有较短的平均路径长度和较大的聚集系数。最后对一个科研合作的实证网络和仿真网络进行比较,发现两者社团结构具有相同的特征。     

新一轮退耕还林工程多元目标瞄准研究——基于农户决策自主权视角

退耕还林工程进入政策调整的新阶段,新一轮退耕还林工程能否瞄准多元政策目标是这一时期的关键问题。本文基于一手调查的农户及地块数据,考察新一轮退耕还林工程对生态效益、成本有效性、益贫性等多元目标的瞄准成效,并进一步探究农户决策自主权在退耕瞄准过程中的作用。结果表明,新一轮退耕还林工程基本能够瞄准生态效益较高、成本较低的地块,但并未瞄准贫困户的地块,尤其是在农户没有瞄准自主权的情况下,家庭经济贫困对参与新一轮退耕还林有显著负向影响。农户决策自主权对新一轮退耕还林工程瞄准多元目标有积极作用,由农户自主瞄准的地块更具成本有效性和益贫性。因此,为提升退耕还林工程的瞄准效率,实现成本有效性、益贫性等多元目标及成果的可持续性,应在政策实施过程中赋予农户更多决策自主权;改进新一轮退耕还林工程的瞄准方案与指标体系;完善退耕补偿方案,建立动态的、差异化的生态补偿机制等。     

Study on the effect of doxorubicin on expressions of genes encoding myocardial sarcoplasmic reticulum Ca2+ transport proteins and the effect of taurine on myocardial protection in rabbits

To investigate the effect of doxorubicin(DOX) on gene expression of the myocardial sarcoplasmic reticulum (SR)Ca2+ transport proteins and the mechanism of taurine(Tau) protecting cardiac muscle cells, 9 rabbits were injected with DOX , 8 rabbits with DOX and Tau, and 9 rabbits with normal saline. Cardiac function , concentration of calcium in cardiomyocytes (Myo[Ca2+]i), activity of SR Ca2+-ATPase(SERCA2a), level of SERCA2a mRNA and Ca2+ released channels(RYR2)mRNA were detected. The left ventricle tissues were observed by electron microscopy. The results showed that cardiac index, left ventricular systolic pressure, activity of SR Ca2+-ATPase and level of SERCA2a mRNA decreased , while Myo[Ca2+]i increased in DOX-treated rabbits. DOX could not affect the level of RYR2 mRNA. Tau intervention could alleviate the increase of left ventricular diastolic pressure, Myo[Ca2+]i and the decrease of SERCA2a mRNA induced by doxorubicin. The results suggested that downregulation of SERCA2a gene expression was an important mechanism of DOX-induced cardiomyopathy and that Tau could partially improve the heart function by reducing calcium overload and alleviating downregulation of SERCA2a mRNA.