竞争性RT-PCR检测铜对Ctr1 mRNA表达的影响

为了应用竞争 RT- PCR法检测铜对猪传代肾细胞 (PK15 )中特异性铜转运蛋白 Ctr1基因 m RNA表达水平的影响 ,经 2次克隆 ,将筛选出一段 4 0 0 bp的核苷酸序列 ,插入 RT- PCR扩增出的 5 30 bp Ctr1目的片段中 ,构建了插入突变型 Ctr1- c DNA竞争模板。再将竞争模板与各试验组 c DNA同时进行 PCR扩增。结果 ,猪肾 PK15细胞 Ctr1基因m RNA表达量在 7.8～ 31.2 μmol/ L Cu范围内随铜添加浓度的升高减少 ,当铜添加浓度达到 6 2 .5 μmol/ L 时 ,其表达量又有所回升 ,呈双相反应。     

PK15细胞α干扰素效应因子qPCR检测方法的建立及其初步应用

 
为建立一种用SYBR Green I荧光染料检测PK 15细胞α干扰素(α IFN)效应因子Mx1、OAS的mRNA表达水平的qPCR检测方法，通过在猪圆环病毒2型（Porcine Circovirus Type 2, PCV2）抑制α IFN发挥效应的信号通路中进行初步应用。根据GenBank中目的基因的序列，利用分子生物学软件Premier 5.0在其保守区设计并合成相应的特异性引物。利用TRIzol法提取总RNA，经Oligo d(T)15进行反转录，利用PCR扩增各段目的基因，并克隆至pMD 18 T载体，转化大肠杆菌DH 5α，经鉴定为阳性的重组质粒作为标准品模板建立SYBR Green I qPCR标准曲线和溶解曲线，并进行灵敏性、特异性和重复性试验。根据建立的实时qPCR方法，检测PCV2对α IFN效应因子的抑制效果。对建立的PK 15细胞α IFN效应因子SYBR Green I qPCR方法进行分析，结果表明Mx1、OAS和内参β actin基因的Ct值与标准品稀释度在1×101～1×108 copies/μL的范围分别呈良好的线性关系。PK 15细胞在接种PCV2，并受到α IFN刺激后Mx1、OAS的相对表达量较未接种PCV2明显降低。本试验建立了PK 15细胞α IFN效应因子的qPCR检测方法，为在mRNA水平上对PK 15细胞α IFN效应因子的定量分析奠定了基础，并成功地初步应用于PCV2抑制α IFN发挥效应的信号通路研究中。     

Nutrient impoverishment and limitation of productivity after 20 years of conservation management in wet grasslands of north-western Germany

European wet grasslands are characterized by high diversity of plant and animal species but are threatened by intensive land use. Although preservation or restoration of species-rich wet grasslands requires low nutrient availability that could be achieved by long-term management, studies monitoring nutrient removal are lacking. Our objective was to assess the long-term effect of management (mowing twice a year without or with PK fertilization for 20 years) on (i) productivity and nutrient removal with the harvest, (ii) the type of nutrient limitation, and (iii) plant species richness in wet grasslands in north-western Germany considering the differences between organic and mineral soils.Initially low nutrient availability in soil led to decreased productivity and base cation removal with harvest particularly on mineral soils after six years of mowing twice a year without fertilization. On mineral soils, N:K ratios indicated limitation of plant growth by K. On organic soils, neither productivity nor K removal with the harvest changed with time suggesting additional K input probably caused by rising groundwater. On organic soils, K:P ratios and a significant decrease of productivity with increasing N:P ratios suggested P limitation. Plant species richness was maintained or even slightly increased by mowing twice a year without fertilization but mainly comprised species that were already present at the study sites.Productivity and N, P, K, and Mg removal with the harvest was significantly increased by mowing twice a year with PK fertilization while species richness was maintained. After 10 years, N:K ratios indicate K limitation even for mowing twice a year with PK fertilization. In case of initially low nutrient availability in soil, cautious PK fertilization and mowing can be recommended to meet demands of agriculture and nature conservation.     

Lack of gender effect on the pharmacokinetics and pharmacodynamics of dexamethasone in the camel after intravenous administration

The pharmacokinetics and pharmacodynamics of dexamethasone were studied in six male and six female camels after a single intravenous dose (0.05 mgkg(-1) body weight) of dexamethasone. The pharmacokinetic parameters of the two-compartment pharmacokinetic model for female and male camels, respectively (mean+/-SEM) were as follows: terminal elimination half-lives were 8.02+/-1.15 and 7.33+/-0.80 h, total body clearances were 95.5+/-16.0 and 124.5+/-11.9 ml h(-1) per kg, volumes of distribution at steady state were 0.72+/-0.08 and 0.87+/-0.14 litre kg(-1), and the volumes of the central compartment were 0.12+/-0.02 and 0.17+/-0.02 litre kg(-1). There was no significant difference in any pharmacokinetic parameter between female and male camels. Pharmacodynamic effects were evaluated by measuring endogenous plasma cortisol, circulating lymphocytes and neutrophils numbers and were analysed using indirect pharmacokinetic/pharmacodynamic models. The estimated IC50 of dexamethasone for cortisol and lymphocytes for female and male camels were 3.74+/-0.99 and 2.28+/-1.09 and 2.63+/-0.71 and 2.41+/-0.79 ng ml(-1), respectively. The EC50 for neutrophils for female and male camels were 24.5+/-5.83 and 20.2+/-3.82 ng ml(-1), respectively. There was no significant difference in any pharmacodynamic parameter between female and male camels. Dexamethasone in urine could be detected for 4-5 days by enzyme-linked immunosorbent assay and for 3-4 days by liquid chromatography/mass spectrometry after an intravenous dose of 0.05 mg kg(-1) body weight.     

低温对甘蓝逆境生理指标和蛋白质磷酸化的影响

 研究表明, 低温(5 ℃) 逆境处理0～30 min 甘蓝体内的MDA、脯氨酸、可溶性糖、ABA 含量和PK活性等指标在较短的时间内都有明显上升, 然后下降。ABA 含量和PK活性的峰值早于其他指标, 同时低温逆境引起的PK活性对Ca²⁺ 的存在有明显的依赖性, Mn²⁺ 、Mg²⁺ 对其活性也有明显影响, 且这两种离子的影响机制可能不同。低温逆境信号引起22.9 kD 的蛋白质磷酸化。     

Effects of age on the pharmacokinetics of single dose sulfamethazine after intravenous administration in cattle

Sulphonamides are still being used widely, influenced by the low cost and the efficacy against many common bacterial infections, since they present a broad spectrum of activity. The aim of this study was to determine the effect of age on the pharmacokinetic/pharmacodynamics (PK/PD) integration of intravenous sulfamethazine (60 mg/kgbw) in cattle, and the possible therapeutic outcomes. Six healthy female calves, at the age of one, three, seven and fifteen weeks were used. Normality analysis was assessed with the Shapiro-Wilk test. Non-parametric tests for paired data were used. Plasma concentrations were quantified using HPLC/uv. Differences were found between one-three-weeks-old calves and seven-fifteen-weeks-old calves, in pharmacokinetic parameters (clearance, area under the concentration-time curve and elimination half-life) and in the PK/PD integration. The ratios obtained in PK/PD integration (T>MIC, WAUC) confirm that it is necessary to apply twice the dose of sulfamethazine in ≥ 7 weeks-old cattle to reach a satisfactory dosage regimen (MIC ≥ 32 μg/mL).     

小麦抗白粉病基因Pm43定位区段内RGA分析

利用普通小麦测序草图可从基因组范围内对小麦单条染色体上的某个区段进行分析。Pm43是作物遗传与分子改良山西省重点实验室在小麦2D染色体长臂上定位的一个抗白粉病基因。利用信息学方法分析Pm43所在物理图谱、遗传图谱和基因组图谱上的位置,可为其精细定位乃至候选基因的确定提供参考。试验采用Pm43两侧标记序列进行比对,将Pm43定位于染色体C-2DL3-0.49区间的79~99 c M内,所在基因组区段为2DL_9835990~2DL_9823315。利用目前已克隆小麦抗病基因的保守基序作为探针,从目标区段内检索出89条包含抗病基因类似物(Resistance gene analogues,RGA)序列的scaffold,其中,36条scaffold被诊断出含有SSR位点,之后针对SSR位点开发分子标记。利用携带有Pm43的普通小麦材料CH5025、感白粉病材料台长29以及CH5025×台长29的F2作图群体的抗感池DNA,对开发的SSR标记进行连锁性检测,共筛选出4个多态性标记,从而将目标区段进一步确定在标记PK_9908430和NBS_9908778之间。最后经聚类分析,筛选出与已克隆Pm基因同源性较高的1个PK序列和1个NBS序列,且在粗山羊草2D染色体和水稻第4染色体中均存在与这2个序列同源的RGA表达序列。     

猪miR-22前体上游序列突变的PK15细胞系构建

猪miR-22前体上游序列片段突变可能对miR-22的表达起到重要调控作用,为进一步探究其功能,基于CRISPR/Cas9基因编辑技术,通过针对猪miR-22前体上游序列片段设计2个靶标sgRNAs(short guide RNAs),构建重组表达载体pX459-sgRNA1和pX459-sgRNA2;随后将重组质粒转染猪肾上皮细胞系(PK15),经嘌呤霉素初步筛选后,提取基因组DNA,通过PCR及测序鉴定编辑效果;最后,通过实时荧光定量PCR(qRT-PCR)检测编辑前后miR-22相对表达量的变化。结果显示,81个阳性克隆中,共产生6种突变类型,突变率达60.49%;qRT-PCR检测显示,编辑后miR-22的表达量显著下调约50%。本研究成功获得了miR-22前体上游序列突变的猪PK15细胞模型,为今后猪miR-22的功能研究提供了新的可应用研究对象。     

他莫昔芬对猪伪狂犬病病毒体外增殖的影响

【目的】研究他莫昔芬(Tamoxifen)在PK15细胞模型上对猪伪狂犬病病毒(Pseudorabies virus, PRV)感染的抗病毒作用。【方法】以PK15细胞为模型,采用CCK-8细胞计数法检测他莫昔芬对细胞活力的影响;利用ANNEXIN V-FITC/PI凋亡试剂盒检测他莫昔芬对细胞周期和凋亡的影响;利用CytoFLEX流式细胞仪和荧光显微镜检测他莫昔芬处理细胞感染PRV-GFP后病毒增殖的差异;利用实时荧光定量PCR和Western blotting方法分别检测他莫昔芬处理细胞感染PRV-QXX后PRV gB基因mRNA和蛋白表达水平的变化;利用病毒滴度测定法检测他莫昔芬处理细胞感染PRV-QXX后对病毒的抑制情况。【结果】他莫昔芬用药浓度在6μmol/L时对细胞活力无影响;在6μmol/L以下时,与空白组相比,他莫昔芬处理组对细胞周期与凋亡没有显著影响(P>0.05)。在同一时间点,他莫昔芬处理组PRV-GFP在PK15细胞中的增殖速度极显著低于对照组(P<0.01);实时荧光定量PCR结果表明,他莫昔芬处理后极显著抑制了PRV gB基因mRNA在PK15细...