Pnas4 is a novel regulator for convergence and extension during vertebrate gastrulation

Recent studies show that human Pnas4 might be tumor associated, while its function remains unknown. Here, we investigate the developmental function of Pnas4 using zebrafish as a model system. Knocking down Pnas4 causes gastrulation defects with a shorter and broader axis, as well as a posteriorly mis-positioned prechordal plate, due to the defective convergence and extension movement. Conversely, over-expression of Pnas4 mRNA leads to an elongated body axis. We further demonstrate that Pnas4 is required cell-autonomously for dorsal convergence but not for anterior migration. In addition, genetic interaction assays indicate that Pnas4 might act in parallel with non-canonical Wnt signal in the regulation of cell movement. Our data suggest that Pnas4 is a key regulator of cell movement during gastrulation.     

Polycyclic aromatic hydrocarbons and phthalic acid esters in the soil-radish (Raphanus sativus) system with sewage sludge and compost application

We studied the accumulation of polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PAEs) in a latosolic red soil and radish (Raphanus sativus) with application of sewage sludge at rates of 10, 20 and 40 g kg(-1) soil or compost at rate of 10 g kg(-1) soil. In radish the concentrations of individual PAHs and PAEs varied from non-detectable to 803 microg kg(-1) dry weight (d.w.) and from non-detectable to 2048 microg kg(-1) d.w., respectively. Compared to the control, higher application rates of sewage sludge resulted in pronounced increases in shoot, root and soil concentrations of PAHs and PAEs. PAE concentrations in radish grown in soil spiked with sludge compost were higher while the PAH concentrations were comparable to those receiving 10 g kg(-1) of sewage sludge. However, the root biomass of radish in soil amended with compost was significantly higher and the shoot-to-root ratio was significantly lower than in the other treatments. The bioconcentration factors (BCFs, the ratio of contaminant concentration in plant tissue to the soil concentration) of di-n-butyl phthalate and di(2-ethylhexyl) phthalate in both shoots and roots and of total PAH concentrations in roots were less than 1.0, but some BCFs for individual PAHs were high with a maximum value of 80.     

四种渗透性防冻剂在猕猴精子低温冷冻保存中对精子功能状态的影响

以冷冻精子的复苏运动度、荧光染料Hoechst 3 3 2 5 8检测的细胞膜完整率、异硫氰酸荧光素标记的花生凝集素 (FITC PNA)检测的顶体完整率作为精子功能状态的指标 ,对甘油、二甲亚砜、乙二醇和丙二醇 4种常用渗透性防冻剂在猕猴精子冷冻保存过程中的作用进行了比较。结果表明 :冷冻保存精子的复苏运动度 ,甘油 ( 4 7 3± 5 7% )和乙二醇 ( 4 4 8± 6 7% ) >二甲亚砜 ( 2 2 9± 0 9% ) >丙二醇 ( 0± 0 % ) ;细胞膜完整率 ,甘油 ( 5 4 8± 3 2 % )和乙二醇 ( 5 4 0± 6 7% ) >二甲亚砜 ( 3 7 5± 7 0 % ) >丙二醇 ( 2 8 3± 6 5 % ) ;顶体完整率 ,甘油 ( 82 2± 2 4 % )和乙二醇 ( 82 4± 2 4 % ) >二甲亚砜 ( 6 8 7± 5 7% )和丙二醇 ( 72 3±3 5 % ) (P <0 0 5 )。结果提示 :二甲亚砜和丙二醇 ,尤其是丙二醇并不适合猕猴精子的冷冻保存 ;而乙二醇具有和甘油相似的保护作用 ,是一种极具潜力的猕猴精子冷冻保存的渗透性防冻剂。     

Sorting of furin in polarized epithelial and endothelial cells: expression beyond the Golgi apparatus.

The conversion of proteins into their mature forms underlies the functionality of many fundamental cellular pathways. One posttranslational modification leading to maturation of precursor proteins consists of the cleavage of their prodomain at pairs of basic amino acids by enzymes of the subtilisin-like mammalian proprotein convertase family. One of these enzymes, furin, acts in the constitutive secretory pathway of almost every cell type. However, in spite of furin's major roles in many pathophysiological processes, the exact subcellular sites of processing and activation of its substrates remain elusive. In this study, furin antigenic sites were tracked in subcellular compartments of various tissues and corresponding cell lines by high-resolution immunogold electron microscopy, Western blotting, cell transfection, and in vivo gene delivery of the furin cDNA. In addition to the Golgi apparatus, furin was assigned to endosomes and plasma membranes of polarized intestinal and renal epithelial cells and endothelial cells of the continuous, fenestrated, and discontinuous capillaries. Roles of furin in endothelial permeability, basement membrane turnover, and shedding of transmembrane proteins are supported by our data.     

Towards the biocontrol of bindweeds with a mycoherbicide

Within the framework of the European COST Action 816, afive-year collaboration between scientists from five Europeancountries has made an important contribution to biologicalcontrol of field and hedge bindweeds (Convolvulus arvensis andCalystegia sepium, respectively). A fungus Stagonosporaconvolvuli strain LA39, able to infect both field and hedgebindweed, was found in the UK and its biocontrol efficacyimproved by optimising mass production, formulation and storagetechniques. This fungus controlled bindweeds in both a cemeteryand in maize crops. Its use fits best in an integrated pestmanagement system where a green cover controls most of the weedsexcept the bindweeds. DNA marker analyses indicate that thefungus reproduces sexually, which could be used to furtherimprove this mycoherbicide. In addition, the insect Melanagromyzaalbocilia, which itself exhibits biocontrol potential againstbindweeds, may be used in combination with LA39 to improve theability of the fungus to penetrate the stem of bindweeds.Overall, the results suggest that S. convolvuli LA39 haspromising potential as a bioherbicide for control of field andhedge bindweed.     

Endophilin A2-mediated alleviation of endoplasmic reticulum stress-induced cardiac injury involves the suppression of ERO1α/IP3R signaling pathway

Cardiac injury upon myocardial infarction (MI) is the leading cause of heart failure. The present study aims to investigate the role of EndoA2 in ischemia-induced cardiomyocyte apoptosis and cardiac injury. In vivo, we established an MI mouse model by ligating the left anterior descending (LAD) coronary artery, and intramyocardial injection of adenoviral EndoA2 (Ad-EndoA2) was used to overexpress EndoA2. In vitro, we used the siRNA and Ad-EndoA2 transfection strategies. Here, we reported that EndoA2 expression was remarkably elevated in the infarct border zone of MI mouse hearts and neonatal rat cardiomyocytes (NRCMs) stimulated with oxygen and glucose deprivation (OGD) which mimicked ischemia. We showed that intramyocardial injection of Ad-EndoA2 attenuated cardiomyocyte apoptosis and reduced endoplasmic reticulum (ER) stress in response to MI injury. Using siRNA for knockdown and Ad-EndoA2 for overexpression, we validated that knockdown of EndoA2 in NRCMs exacerbated OGD-induced NRCM apoptosis, whereas overexpression of EndoA2 attenuates OGD-induced cardiomyocyte apoptosis. Mechanistically, knockdown of EndoA2 activated ER stress response, which increases ER oxidoreductase 1α (ERO1α) and inositol 1, 4, 5-trisphosphate receptor (IP₃R) activity, thus led to increased intracellular Ca²⁺ accumulation, followed by elevated calcineurin activity and nuclear factor of activated T-cells (NFAT) dephosphorylation. Pretreatment with the IP₃R inhibitor 2-Aminoethoxydiphenylborate (2-APB) attenuated intracellular Ca²⁺ accumulation, and pretreatment with the Ca²⁺ chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA) or the calcineurin inhibitor Cyclosporin A (CsA) inhibited EndoA2-knockdown-induced NRCM apoptosis. Overexpression of EndoA2 led to the opposite effects by suppressing ER-stress-mediated ERO1α/IP₃R signaling pathway. This study demonstrated that EndoA2 protected cardiac function in response to MI via attenuating ER-stress-mediated ERO1α/IP₃R signaling pathway. Targeting EndoA2 is a potential therapeutic strategy for the prevention of postinfarction-induced cardiac injury and heart failure.     

茶毛虫性引诱剂诱杀效果分析

20 0 2年在贵州省都匀茶场研究了茶毛虫性信息素引诱剂大面积诱杀茶毛虫的防治效果 ,并观察了不同浓度以及不同高度设置对诱蛾效果的影响。结果表明 :越冬代试验 2 0d ,诱杀成虫 42 60头 ,第1代试验 44d ,诱杀成虫 1 3 42 3头 ;防治后田间落卵量以及后代幼虫数分别比对照区减少 5 3 3 3 %和60 5 3 % ;诱蛾效果以浓度为 1 5mg 枚的诱芯效果最好 ,诱盆设置高度以 90cm左右为佳。     

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     

马尾松诱导抗性对马尾松毛虫幼虫生长发育的影响

利用不同受害方式和受害程度的马尾松 (PinusmassonianaLamb.)针饲养马尾松毛DendrolimuspunctarusWalker虫幼虫 ,研究受害松针对幼虫生长发育的影响。结果表明 :马尾松毛虫取食受害松针后 ,幼虫的取食量下降 ,排粪量减少 ,对食物的消耗和利用指数降低 ,幼虫发育速率缓慢 ,死亡率增加 ,从而影响马尾松毛虫的种群动态     

cAMP and sodium transport in the freshwater crayfish, Cherax destructor

Crayfish in which sodium absorption was maximally stimulated had elevated levels of both cAMP and Na⁺-K⁺-ATPase activity in gill tissue. The concentration of cAMP and activity of Na⁺-K⁺-ATPase in gill tissue were monitored following transfer of crayfish from water containing 125 mmol.l⁻¹ Na to Na-free media. Both parameters were significantly elevated within 10 min of transfer to Na-free media and [cAMP] peaked between 1 and 2 h before falling transiently to the control level at 3 h. A second peak of [cAMP] and a further rise in Na⁺-K⁺-ATPase activity were evident 6 h after transfer and elevated levels were then maintained. The pattern observed was consistent with the existence of two separate mechanisms for the control of sodium absorption both of which stimulated the activity of Na⁺-K⁺-ATPase via elevation of the intracellular concentration of cAMP. The initial response was very rapid (<10 min) but of brief duration (1–2 h) and this mechanism appeared to be sensitive to changes in external ion levels. The second mechanism exhibited a much longer response time (3–6 h) and duration and was likely to be sensitive to changes in internal ion concentrations.