Effects of water discharge on fledging time,growth, and survival of piping plovers on the Missouri River

River flow management and modification is a global issue, and its effects on river-dependent organisms are pervasive. Flow modification can directly affect avian species through mortality or habitat loss, but less is known about indirect and sublethal effects of flow modification on reproductive output in these species. Young birds are more vulnerable to predation between hatching and fledging than after flight is achieved, but tradeoffs must be made to balance growth and survival. Predation pressure appears to be a significant factor affecting the time to fledging in altricial birds, but less is known about this threat for precocial birds. Birds reaching fledging earlier should have greater rates of survival to migration because their predator escape repertoire includes flight at an earlier age. We evaluated the effect of varying outflows from the Gavins Point Dam on the growth, age at fledging, and survival of piping plover (Charadrius melodus) chicks on the Missouri River (2006–2009). The study was characterized by 2 relatively high flow years (2006 and 2009) and 2 relatively low flow years (2007 and 2008). We used success rate in recapturing chicks in capture–mark–recapture models as an index for fledging. We attempted to recapture all chicks (n = 1,099) by hand every 3–4 days throughout the season to acquire morphological measurements. Models indicated that as flows from the dam increased, age at fledging increased. We also found that increasing flows were associated with decreasing daily survival rates (β_flow = −2.401, 95% CI: −4.351 to −0.452). Flow was also negatively related to chick mass gain, but we found less evidence for an effect on wing-chord length. Increased flows covered wet-substrate foraging habitat, and likely affected plover reproductive output directly through chick survival and indirectly through decreased growth and increased fledging times. © The Wildlife Society, 2013     

高山被孢霉产花生四烯酸及其遗传改造的研究进展

花生四烯酸作为一种重要的多价不饱和脂肪酸,因其具有多种生理功能而被认为是潜在的食品添加剂和药物。近年来,利用高山被孢霉合成花生四烯酸已成为研究热点。前期相关研究主要集中在菌种选育及发酵调控方面。随着研究的不断深入,关于高山被孢霉合成花生四烯酸的代谢途径的研究取得了较大进展。以下简要概述前期工作进展,着重论述花生四烯酸合成途径的关键酶及其高山被孢霉的遗传改造的研究情况,包括生物合成花生四烯酸代谢途径、关键酶及其应用、高山被孢霉的遗传操作系统的构建以及遗传改造的应用,并对其研究前景进行了展望。     

Molecular epidemiology of plasmid mediated resistance to fosfomycin among bacteria isolated from different environments

In this report we present data on the dispersion of a gene responsible for the plasmid-mediated resistance to fosfomycin among bacteria isolated from four hospitals and seven geographically separated domestic sewage treatment plants. Colony hybridization experiments, using a 0.85 kbp DNA fragment which carried the fosfomycin resistance determinant, have shown that the gene was present in isolates from three hospitals and six sewage plants although with different incidence and that it is carried by species of Enterobacteriaceae, Pseudomonas, Acinetobacter, Staphylococcus and Bacillus .     

Exploiting dendritic cells for cancer immunotherapy: genetic modification of dendritic cells

Dendritic cells (DCs) are pivotal regulators of immune reactivity and immune tolerance. The observation that DCs can recruit naive T cells has invigorated cancer immunology and led to the proposal of DCs as the basis for vaccines designed for the treatment of cancer. Designing effective strategies to load DCs with antigens is a challenging field of research. The successful realization of gene transfer to DCs will be highly dependent on the employed vector system. Here, we review various viral and non-viral gene transfer systems, and discuss their distinct characteristics and possible advantages and disadvantages in respect to their use in DC-based immunotherapy.     

In silico annotation of unreviewed acetylcholinesterase (AChE) in some lepidopteran insect pest species reveals the causes of insecticide resistance

Lepidoptera is the second most diverse insect order outnumbered only by the Coeleptera. Acetylcholinesterase (AChE) is the major target site for insecticides. Extensive use of insecticides, to inhibit the function of this enzyme, have resulted in the development of insecticide resistance. Complete knowledge of the target proteins is very important to know the cause of resistance. Computational annotation of insect acetylcholinesterase can be helpful for the characterization of this important protein. Acetylcholinesterase of fourteen lepidopteran insect pest species was annotated by using different bioinformatics tools. AChE in all the species was hydrophilic and thermostable. All the species showed lower values for instability index except L. orbonalis, S. exigua and T. absoluta. Highest percentage of Arg, Asp, Asn, Gln and Cys were recorded in P. rapae. High percentage of Cys and Gln might be reason for insecticide resistance development in P. rapae. Phylogenetic analysis revealed the AChE in T. absoluta, L. orbonalis and S. exigua are closely related and emerged from same primary branch. Three functional motifs were predicted in eleven species while only two were found in L. orbonalis, S. exigua and T. absoluta. AChE in eleven species followed secretory pathway and have signal peptides. No signal peptides were predicted for S. exigua, L. orbonalis and T. absoluta and follow non secretory pathway. Arginine methylation and cysteine palmotylation was found in all species except S. exigua, L. orbonalis and T. absoluta. Glycosylphosphatidylinositol (GPI) anchor was predicted in only nine species.     

Polyglutamylation: a fine‐regulator of protein function?

Polyglutamylation is a post-translational modification in which glutamate side chains of variable lengths are formed on the modified protein. It is evolutionarily conserved from protists to mammals and its most prominent substrate is tubulin, the microtubule (MT) building block. Various polyglutamylation states of MTs can be distinguished within a single cell and they are also characteristic of specific cell types or organelles. Polyglutamylation has been proposed to be involved in the functional adaptation of MTs, as it occurs within the carboxy-terminal tubulin tails that participate directly in the binding of many structural and motor MT-associated proteins. The discovery of a new family of enzymes that catalyse this modification has brought new insight into the mechanism of polyglutamylation and now allows for direct functional studies of the role of tubulin polyglutamylation. Moreover, the recent identification of new substrates of polyglutamylation indicates that this post-translational modification could be a potential regulator of diverse cellular processes.     

限制和修饰系统LlaBIII在构建抗噬菌体菌株中的作用

限制和修饰 (ｒｅｓｔｒｉｃｔｉｏｎａｎｄｍｏｄｉｆｉｃａｔｉｏｎ ,Ｒ Ｍ)系统是指由限制性内切酶和甲基化酶组成的单亚基或多亚基复合酶系统 ,两者通常成对出现 ,具有相同的ＤＮＡ识别位点 ,其作用相反。Ｒ Ｍ系统在原核生物中普遍存在 ,在保护细胞免遭外源病毒侵害方面具有重要作用[1] 。作为发酵剂的乳酸乳球菌在乳制品发酵中具有重要作用 ,但这类菌株极易遭受噬菌体感染 ,导致菌株产酸力降低 ,甚至发酵失败 ,造成严重的经济损失。所以在乳制品发酵过程中防止噬菌体感染就成为十分重要的问题。通过自然筛选或诱变处理等手段筛选噬菌…     

5-s-Cysteinyl-conjugates of catecholamines induce cell damage,extensive DNA base modification and increases in caspase-3 activity in neurons

A decrease in reduced glutathione levels in dopamine containing nigral cells in Parkinson's disease may result from the formation of cysteinyl-adducts of catecholamines, which in turn exert toxicity on nigral cells. We show that exposure of neurons (CSM 14.1) to 5-S-cysteinyl conjugates of dopamine, L-DOPA, DOPAC or DHMA causes neuronal damage, increases in oxidative DNA base modification and an elevation of caspase-3 activity in cells. Damage to neurons was apparent 12-48 h of post-exposure and there were increases in caspase-3 activity in neurons after 6 h. These changes were paralleled by large increases in pyrimidine and purine base oxidation products, such as 8-OH-guanine suggesting that 5-S-cysteinyl conjugates of catecholamines are capable of diffusing into cells and stimulating the formation of reactive oxygen species (ROS), which may then lead to a mechanism of cell damage involving caspase-3. Indeed, intracellular ROS were observed to rise sharply on exposure to the conjugates. These results suggest one mechanism by which oxidative stress may occur in the substantia nigra in Parkinson's disease.     

Characterization of acrolein-induced protein cross-links

Lipid peroxidation products contribute to protein aggregation that occurs during oxidative stress in a number of degenerative disorders. Acrolein (ACR), a highly toxic lipid peroxidation aldehyde, is a strong cross-linking agent of cellular components such as proteins. To understand the mechanisms of oxidative stress-induced protein aggregation, this study characterized the ACR modification of chain B from bovine insulin by mass spectrometry. To identify the cross-linking sites, the ACR-treated peptide was digested with a protease and the resulting peptides were analysed by liquid chromatography-tandem mass spectrometry. Inter- and intra-molecular cross-linking adducts were identified between amino groups and the side chain of histidine in the peptide. These results indicated that the ACR-induced cross-links were accompanied by two reactions, namely Michael addition and Schiff base formation. In conclusion, the use of mass spectrometric techniques provided chemical evidence for protein cross-linking with ACR.