大黄鱼肿瘤抑制因子cylindromatosis (LcCYLD)的序列与免疫反应特征及其功能

为研究大黄鱼肿瘤抑制因子cylindromatosis（CYLD）在免疫反应中的作用,本实验克隆了大黄鱼CYLD的全长cDNA（命名为LcCYLD）并对其进行序列分析;采用荧光定量PCR的方法对大黄鱼各组织及免疫刺激后的大黄鱼肾细胞系中的LcCY LD表达变化进行检测;构建了重组表达载体pTurboGFP-CYLD及pcDNA3.1-CYLD,分别用于亚细胞定位实验及过表达实验;在HEK293T细胞系中过表达LcCYLD后采用双荧光素酶报告系统检测了 NF-κB、TNF-α及IL-1β 启动子活性的变化。结果显示,LcCYLD的ORF包含2 754 bp,编码917个氨基酸,推测具有保守的3个N端的CAP-GLY结构域,1个磷酸化区域和1个C端的UCH结构域,多序列比对结果显示各物种CYLD间高度保守;系统进化分析显示,LcCYLD与来源于其他硬骨鱼的CYLD聚为一支,其中与条纹鲈的CYLD关系最近;转录水平表达分析发现LcCYLD在大黄鱼各组织均有表达,其中在脑中表达量最高;LPS及poly I:C刺激能够显著诱导LcCYLD的表达;亚细胞定位实验表明LcCYLD在细胞质及细胞核中均有表达;过表达LcCYLD能够显著抑制NF-κB及促炎细胞因子TNF-α及IL-1β的转录激活。以上研究结果表明大黄鱼CYLD能够抑制NF-κB的转录激活,为深入了解LcCYLD在大黄鱼先天免疫信号转导中的作用奠定基础。     

棕点石斑鱼中草药免疫增强剂的快速筛选

采用离体外周血白细胞与中草药水提液共同孵育法,快速筛选棕点石斑鱼中草药免疫增强剂。39种生药量浓度为100 mg/ml 的中草药水提液及添加5.0 mg/ml 酵母聚糖的中草药水提液分别与棕点石斑鱼外周血白细胞孵育后,采用氮蓝四唑(NBT)还原法检测各种中草药水提液对棕点石斑鱼外周血白细胞氧呼吸爆发活性的影响,再以吞噬乳胶微球法检测具有显著增强白细胞氧呼吸爆发活性效果的中草药对棕点石斑鱼白细胞吞噬活性的影响,筛选中草药免疫增强剂,并将其拌料饲喂棕点石斑鱼,考察其对棕点石斑鱼外周血和头肾白细胞氧呼吸爆发活性的影响。结果显示,39种中草药中有10种对棕点石斑鱼离体白细胞氧呼吸爆发活性显著提高15%以上,3种酵母聚糖添加组对白细胞氧呼吸爆发活性提高70%以上;筛选出可同时提高棕点石斑鱼离体白细胞的氧呼吸爆发活性和吞噬活性的 3种中草药,它们分别为鸡血藤、黄柏和墨旱莲。拌料饲喂实验结果显示,饲喂1%的鸡血藤、黄柏和墨旱莲可显著提高棕点石斑鱼体内外周血和头肾白细胞氧呼吸爆发活性。     

Effects of size and morphology on swimming performance in juvenile brown trout (Salmo trutta L.)

Abstract –  Our study assesses swimming capacity (speed and stamina) and possible morphometric determinants of locomotor performance of juvenile brown trout ( Salmo trutta L.). We addressed these issues at the individual level to have an approach of the functional significance of intraspecific variation in morphological design. Both swimming speed and endurance time showed significant positive relationships with fish length. Size-corrected values of speed and endurance time were negatively correlated suggesting a phenotypic trade-off between burst and prolonged swimming. Size was also highly correlated with all the morphological variables measured. Therefore, we used the residuals of the regressions of those variables on fish length to remove the effect of body size. A principal components analysis (PCA) summarised the 12 morphological variables into two factors, which accounted for 44.3% of the variance. PC1 combined several measures of body depth and width, whereas PC2 represented mainly postanal length relative to abdomen length. Relationships between the scores of the two factors and size-corrected values of maximum swimming speed and endurance time were weak. PC2 showed a significant positive relationship with endurance time; that is, individuals with longer caudal regions were able to swim against water flow for longer periods of time. Stoutness (PC1) showed a marginally significant negative correlation with endurance time. The lack of stronger relationships could be because of the low morphometric variability among the test individuals, all proceeding from the same population, reared in a common environment, and measured at the same ontogenetic stage.     

Growth and weed suppression ability of common and new cover crops in Germany

Cover crops have a wide-ranging influence on the agroecosystem and create multiple benefits for farmers. A major benefit of cover crops is the suppression of weeds during fall and winter, which can help to reduce soil tillage and herbicide use. However, only a small number of cover crop species are currently grown in Germany. To enlarge this number, four new cover crop species including tartary buckwheat, forage radish, red oat and grain amaranth were tested in comparison with common cover crop species such as white mustard, oilseed radish and phacelia. Emergence, soil coverage, dry matter production and weed suppression ability was assessed for all cover crop species. White mustard emerged faster than all other cover crops and produced the highest amount of shoot dry matter at both locations in southwest Germany twelve weeks after planting (WAP). Oilseed radish was the only cover crop that reduced the weed dry matter in all experiments eight WAP. Phacelia was able to reduce weed density by 77% at Meiereihof twelve WAP. Tartary buckwheat offered the highest soil coverage four WAP, produced the greatest shoot dry matter eight WAP and reduced weed dry matter by more than 96% at Meiereihof and Ihinger Hof twelve WAP. Forage radish produced the highest root dry matter and reduced spring weed density by more than 81% in all experiments. Red oat and grain amaranth emerged slowly, produced less biomass than other cover crops and did not suppress weed growth. The results show that tartary buckwheat and forage radish are well suited as new cover crops in Germany due to their fast growth and good weed suppression ability.     

Neutrophil function in septic dogs

BACKGROUND: Leukocytes appear to enter a hypo-inflammatory state in human patients with a severe bacterial infection, whereas, in swine, intra-abdominal sepsis produces an initial increase and subsequent decrease in neutrophil Fc receptor mediated phagocytosis. HYPOTHESIS: Impaired neutrophil function (hypo-inflammatory state) develops in dogs with sepsis. ANIMALS: Thirteen adult client-owned dogs that developed clinical signs consistent with sepsis were assessed for evidence of neutrophil dysfunction. These results were compared with those of 12 healthy dogs. METHODS: Flow cytometry combined with the appropriate fluorescent markers allowed for quantification of the phagolysosomal oxidative burst after Fc receptor-mediated phagocytosis of immune complexes, neutrophil phagocytosis of opsonized Escherichia coli, and the intracellular concentration of reduced glutathione as a measure of oxidative stress. RESULTS: The phagolysosomal oxidative burst after Fc receptor-mediated phagocytosis was significantly lower in neutrophils from septic dogs (mean fluorescence intensity +/- standard deviation; 118 +/- 13 and 165 +/- 27 for septic and control dogs, respectively, p = 0.001), although the phagocytosis of opsonized E. coli was significantly increased (155 +/- 74 and 77 +/- 44 for septic and control dogs, respectively, p = 0.004). Intracellular reduced glutathione was not significantly different in neutrophils from septic and healthy control dogs. CONCLUSIONS: An important component of neutrophil function is decreased in septic dogs. The diminished oxidative burst after Fc receptor-mediated phagocytosis in neutrophils from septic dogs could hinder the ability of the innate immune system to clear bacterial infections or it might help protect these patients from the systemic consequences of infection.     

A review of the potential for competitive cereal cultivars as a tool in integrated weed management

Competitive crop cultivars offer a potentially cheap option to include in integrated weed management strategies (IWM). Although cultivars with high competitive potential have been identified amongst cereal crops, competitiveness has not traditionally been considered a priority for breeding or farmer cultivar choice. The challenge of managing herbicide‐resistant weed populations has, however, renewed interest in cultural weed control options, including competitive cultivars. We evaluated the current understanding of the traits that explain variability in competitive ability between cultivars, the relationship between suppression of weed neighbours and tolerance of their presence and the existence of trade‐offs between competitive ability and yield in weed‐free scenarios. A large number of relationships between competitive ability and plant traits have been reported in the literature, including plant height, speed of development, canopy architecture and partitioning of resources. There is uncertainty over the relationship between suppressive ability and tolerance, although tolerance is a less stable trait over seasons and locations. To realise the potential of competitive crop cultivars as a tool in IWM, a quick and simple‐to‐use protocol for assessing the competitive potential of new cultivars is required; it is likely that this will not be based on a single trait, but will need to capture the combined effect of multiple traits. A way needs to be found to make this information accessible to farmers, so that competitive cultivars can be better integrated into their weed control programmes.     

Teasing apart socially‐induced infertility in non‐reproductive female Damaraland mole‐rats,Fukomys damarensis (Rodentia: Bathyergidae)

The Damaraland mole‐rat is a subterranean mammal exhibiting extreme reproductive skew with a single reproductive female in each colony responsible for procreation. Non‐reproductive female colony members are physiologically suppressed while in the colony, exhibiting reduced concentrations of plasma luteinizing hormone (LH) and a decreased response of the pituitary, as measured by the release of bioactive LH, to an exogenous dose of gonadotrophin releasing hormone (GnRH). Removal of the reproductive female from the colony results in an elevation of LH and an enhanced response of the pituitary to a GnRH challenge in non‐reproductive females comparable to reproductive females, implying control of reproduction in these individuals by the reproductive female. The Damaraland mole‐rat is an ideal model for investigating the physiological and behavioral mechanisms that regulate the hypothalamo–pituitary–gonadal axis. In contrast, we know less about the control of reproduction at the level of the hypothalamus. The immunohistochemistry of the GnRH system of both reproductive and non‐reproductive female Damaraland mole‐rats has revealed no significant differences with respect to morphology, distribution or numbers of immunoreactive GnRH perikarya. We examined whether the endogenous opioid peptide beta‐endorphin was responsible for the inhibition of the release of the GnRH from the neurons indirectly by measuring LH concentrations in these non‐reproductive females following single, hourly and 8 hourly injections of the opioid antagonist naloxone. The results imply that the endogenous opioid peptide, beta‐endorphin, is not responsible for the inhibition of GnRH release from the perikarya in non‐reproductive females. Preliminary data examining the circulating levels of cortisol also do not support a role for circulating glucocorticoids. The possible role of kisspeptin is discussed.     

纽荷尔脐橙贮藏枯水相关ESTs分离与初步分析

 为分析柑橘果实贮藏过程中枯水相关特异基因的表达情况,以纽荷尔脐橙（Citrus Sinensis Osbeck）采摘后贮藏至略见枯水果实的果肉为测验方（Tester）,以刚采摘果实的果肉为驱动方（Driver）,采用抑制性差减杂交（Suppression Subtractive Hybridization,SSH）技术成功构建了贮藏果实差减cDNA文库,共获得656个阳性克隆。随机挑取克隆进行菌液PCR分析,插入片段长度主要集中在100 ~ 1 000 bp。成功对213个克隆进行测序,获得有效序列143条,经序列分析,共得到53条uniESTs序列。在NCBI基因库中对这53个uniESTs进行BLAST分析,比对结果参照MIPS的分类标准,按功能分为14类,其中参与代谢、能量及蛋白合成的ESTs最多,分别占到了全部ESTs的17%、11%和13%。     

黄瓜霜霉病抗性相关基因的初步研究

 以黄瓜高抗霜霉病自交系为材料,构建了两个抑制差减文库,经反向Northern杂交筛选、测序和序列比对,筛选到3个未知功能抗病相关基因。荧光实时定量RT-PCR分析结果表明,未知功能抗病相关基因2I15（GD254229）、3C19（GD254243）和1O08（GD254207）在抗病自交系接种霜霉病病原菌后,可早期高丰度特异上调表达,而在感病自交系中特异上调表达丰度较低或被特异抑制表达。水杨酸（SA）可诱导1O08特异上调表达,抑制2I15和3C19的表达;茉莉酸（JA）处理可诱导1O08特异上调表达,而抑制2I15的表达。ABA处理可显著诱导3C19和1O08特异上调表达,而抑制2I15的表达。机械伤害、高盐、冷害和热激等其它非生物胁迫可显著抑制或诱导这些基因的表达,因此推测,所筛选到的功能未知基因可能具有参与生物和非生物胁迫反应的作用     

利用抑制消减杂交技术分离辣椒细胞质雄性不育育性恢复相关EST

 以辣椒(Capsicum annuum L. ) 细胞质雄性不育系23A、121A, 和其相应的近等基因恢复系23C、121C为试验材料, 利用抑制消减杂交( SSH) 技术成功构建了CMS恢复基因诱导表达的消减cDNA文库。结合高密度点阵膜杂交差异筛选, 获得了282个阳性克隆。通过测序, 除去重复序列共得到175个Unique ESTs。在GenBank上进行BLAST分析, 55个EST片段未找到对应的同源序列, 可能代表了新基因;120个EST片段找到了对应的同源序列, 包括103个已知功能基因和17个未知功能基因。按照MIPS功能分类法, 将其分为14个功能组, 涉及代谢、胁迫应答、蛋白活性、转录因子、信号转导等多方面的功能。