绵羊心脏脂肪酸结合蛋白基因单核苷酸多态性分析

试验旨在探讨心脏脂肪酸结合蛋白（heart fatty acid-binding protein，H-FABP）基因在绵羊中的遗传多态性，并寻找可用于辅助选择的分子标记。本研究以滩羊（250只）及滩羊×湖羊杂交F1代（174只）为试验动物，利用SNaPshot分型技术对H-FABP基因（GenBank登录号：AY157617）的多态位点进行单核苷酸多态性（SNP）分析，统计基因频率和基因型频率，进行Hardy-Weinberg平衡性检测，计算期望杂合度（He）、多态信息含量（PIC）和有效等位基因数（Ne）等遗传多态指标，分析候选基因不同基因型与体重、体长、体高、胸围、胸深、胸宽和管围等生长性状的关联性。结果显示：①检测到9个多态位点：939[A/G]、980[G/A]、1018[T/C]、2878[C/T]、2956[C/T]、3017[G/A]、3341[G/C]、3394[T/A]、1056[-/G]，其中有6处转换、2处颠换、1处单碱基插入。②939[A/G]、980[G/A]、2956[C/T]、3341[G/C]、3394[T/A]和1018[T/C]的He为0.3200~0.4666，PIC为0.2688~0.3577；2878[C/T]、3017[G/A]位点的He为0.0283~0.1272，PIC为0.0279~0.1191，为低度多态；1056[-/G]位点的He在滩羊、滩羊×湖羊杂交F1代群体中分别为0.0120和0，PIC在滩羊、滩羊×湖羊杂交F1代群体中分别为0.0119和0；9个多态位点在滩羊、滩羊×湖羊杂交F1代群体中均符合Hardy-Weinberg平衡定律。③5个多态位点：939[A/G]、980[G/A]、2956[C/T]、3341[G/C]、3394[T/A]处于紧密连锁（D'>0.99），将H-FABP基因分为3个单倍型：AA、AB和BB。④在41只滩羊×湖羊杂交F1代羊中，BB单倍型在各生产性状上具有最大值，但各单倍型间差异不显著（P>0.05）。结果表明，绵羊H-FABP基因具有丰富的遗传多态性，939[A/G]、980[G/A]、2956[C/T]、3341[G/C]、3394[T/A]5个位点紧密连锁，BB单倍型可能是与绵羊生产性状相关的优势单倍型。     

Construction and Partial Biological Characteristics Analysis of Listeriolysin S llsB Gene Deletion Strain

In order to analyze the effect of listeriolysin S (LLS) llsB gene deletion on the biological characteristics of Listeria monocytogenes (LM),this study used homologous recombination to construct the llsB gene deletion strain LM90-ΔllsB,and the biological characteristics of growth characteristics,median lethal dose (LD₅₀) and organ-borne bacteria were studied in healthy Kunming male mice at 8 weeks old and weighing 40 g±5 g.The llsB gene deletion strain was successfully constructed,and the deletion strain had good genetic stability through continuous passage to 20 generations in vitro.Based on its growth curve examination,we found that the growth rate of the mutant strain was slightly higher than that of the parent strain.The results of mice infection test showed that the LD₅₀ of the parent strain and the deletion strain were 10^6.17 and 10^6.50 CFU,respectively.Compared with the parent strain,the amount of bacteria load of the deletion strain in the liver and spleen of the mice was extremely significantly decreased (P<0.01),the results showed that the infection ability of the mutant strain on mice was obviously weakened.No Listeria monocytogenes was detected in the brain.The results suggested that llsB gene might have direct or indirect regulatory effect on some biological characteristics of LM90,and it would provide a theoretical basis for further understanding of the pathogenic mechanism of LLS,prevention and control of listeriosis.     

马疱疹病毒1型主要毒力基因分析及TK基因缺失载体的构建

为了解新疆马疱疹病毒1型（EHV-1）主要毒力基因遗传进化情况并构建TK基因缺失株，本研究以EHV-1 XJ2015株DNA为模板，对其主要毒力基因TK、gI和gE全长进行克隆、测序及生物信息学分析，并扩增TK基因左右重组臂TKL和TKR，构建质粒pUC-TKLR，将扩增后的增强绿色荧光蛋白（EGFP，含有CMV+polyA）插入pUC-TKLR质粒，构建TK基因缺失打靶质粒。TK、gI和gE基因同源性分析结果显示，XJ2015株与国外EHV-1分离株TK、gI和gE基因同源性均较高，分别为99.8%~100.0%、99.6%~100.0%和99.9%~100.0%；与EHV-3分离株同源性均最低，分别为72.9%、59.4%和62.1%；遗传进化分析显示，3个基因均与国外EHV-1同属于一个遗传进化分支，与EHV-9和EHV-4进化关系较近，但与EHV-3进化关系较远，表明XJ2015毒株与国外EHV-1毒株TK、gI、gE基因核苷酸上差异不明显，没有明显的地域性特征，功能基因保守且进化缓慢，同源基因功能相同或相近；经PCR扩增、酶切、测序及转染鉴定，本试验成功构建了用于TK基因缺失的打靶质粒pUC-TKLR-EGFP。通过对EHV-1主要毒力基因的分析及TK基因缺失打靶载体的构建，为新疆地区马鼻肺炎流行病学调查分析、TK基因缺失株的构建提供理论依据。     

表达猪乳铁蛋白肽重组屎肠球菌对断奶仔猪生长性能的影响及其抗ETEC感染效果研究

本试验以表达猪乳铁蛋白肽的重组屎肠球菌（pNZ8112-PLFcin/Ef）饲喂断奶仔猪，研究其对仔猪生长性能的影响和抗产肠毒素大肠杆菌（enterotoxigenic Escherichia coli，ETEC）感染的效果。选取28日龄体重相近的健康断奶仔猪36头，随机分为3组（重组屎肠球菌组、空载体组和培养基组），每组3个重复，每个重复4头仔猪。重组屎肠球菌组和空载体组分别饲喂添加pNZ8112-PLFcin/Ef （6×10¹² CFU/kg）和pNZ8112/Ef （6×10¹² CFU/kg）的基础日粮，而培养基组饲喂含有相同体积的GM17液体培养基的基础日粮。试验期26 d。结果显示，与培养基组相比，重组屎肠球菌组断奶仔猪的平均日增重极显著提高（P<0.01）；料重比显著降低（P<0.05）；腹泻率明显降低，肠道菌群的均匀度和多样性指数均下降。为进一步探究表达猪乳铁蛋白肽的重组屎肠球菌对断奶仔猪抵抗ETEC感染的保护作用，在连续饲喂21 d后，每个重复中随机挑选1头体况相近的断奶仔猪灌服ETEC。结果发现，与培养基组相比，攻菌后重组屎肠球菌组断奶仔猪血清白细胞介素-2（IL-2）、免疫球蛋白G （IgG）含量、肠黏液中分泌型免疫球蛋白A （sIgA）水平均显著升高（P<0.05）；脾脏指数显著提高（P<0.05），但胸腺指数、肠段长度及重量则均无显著差异（P>0.05）。综上所述，表达猪乳铁蛋白肽的重组屎肠球菌能够起到促进断奶仔猪生长及抗ETEC感染的保护作用。     

Application of molybdenum fertilizer enhanced quality and production of alfalfa in northern China under non-irrigated conditions

Molybdenum (Mo) is an essential micro-mineral nutrient for plant growth and development. As an important legume forage, alfalfa (Medicago sativa) is frequently planted in marginal lands of northern China where water scarcity and infertile soil are limiting factors for alfalfa production. Mo plays an important role in nitrogen (N) metabolism in general and N fixation in legume species in particular. To evaluate the role of Mo fertilizer in alfalfa quality and production in semi-arid areas of northern China, we conducted a three-year field experiment in Inner Mongolia from 2012 to 2014. Mo fertilizer at the doses of 0, 150 g hm^?2, 300 g hm^?2yr^?1 was applied consecutively across the three years. Application of Mo at 300 g hm^?2yr^?1 significantly increased dry yield of alfalfa in 2014. Crude protein (CP) content of alfalfa without application of Mo exhibited a decline trend from 2012 to 2014. Application of Mo significantly enhanced total CP in 2012 and 2014, and delayed the reduction in total CP across the three years. In contrast to CP, Mo fertilizer had no significant effects on neutral detergent fiber and acid detergent fiber content. In addition, we found that nitrate reductase activity of alfalfa was increased by Mo fertilizer, which may account for the enhanced CP content in alfalfa. These findings highlight that application of Mo fertilizer can be an effective way to improve alfalfa production and quality in semi-arid areas in northern China.     

柑橘褐斑病菌对不同抗性柑橘品种防御酶活性的影响

以柑橘褐斑病高抗品种Lw8,中抗品种L2,高感品种Lw14为实验材料,通过孢子喷雾法使柑橘褐斑病菌感染柑橘叶片,研究接菌0d、1d、2d、3d、6d、8d、10d时,柑橘叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、几丁质酶(CHT)酶和β-1,3葡聚糖酶(GLU)含量及活性变化规律与品种抗病性的关系。结果表明,接种前,两个抗病品种Lw8、L2中的POD、SOD、PAL、PPO 、GLU、CHT活性显著高于高感品种Lw14,CAT活性则与高感品种Lw14相近；接种后,3个不同抗性品种中SOD、POD、CAT、PAL、PPO 、GLU、CHT 7种防御酶活性较对照明显提高,但不同品种增加幅度不一致,除CAT外,其余6种防御酶活性均表现为抗病品种Lw8、L2增幅显著高于高感品种Lw14,且两个抗病品种一般在接菌3d内6种防御酶活性迅速升高并达到峰值；而高感品种Lw14防御酶(除CAT外)活性或增幅较小或较两个抗病品种滞后。本研究初步探讨了不同抗性品种接种褐斑病菌后7种防御酶的活性动态变化与柑橘品种抗病性关系,为进一步研究其抗病机理奠定基础。     

Effect of endothelin-1 on inflammation and oxidative stress in COPD

AIM:To investigate the effect of endothelin-1 on inflammation and oxidative stress in chronic obstructive pulmonary disease (COPD). METHODS:Healthy non-smokers (30 cases), healthy smokers (30 cases) and COPD patients (29 cases) were collected and induced to produce sputum. The concentration of endothelin-1 in the induced sputum was detected. The model of emphysema was established by cigarette smoke extract to stimulate SD rats. Endothelin A receptor antagonist BQ123 and non-selective endothelin receptor antagonist bosentan were used to intervene with the model rats. The experiment was divided into control group, cigarette-treated group, selective antagonist group and non-selective antagonist group. The protein levels of cleaved caspase-3 in the lung tissue were determined by Western blot. Gelatin zymography was used to analyze the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9 in the lung tissue. The levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured by ELISA. The bioantioxidant power (BAP) was detected by BAP assay kit. RESULTS:The concentrations of endothelin-1 in induced sputum of healthy smokers and COPD patients were significantly higher than that of healthy non-smokers (P<0.05), and the level of endothelin-1 in COPD patients was significantly higher than that in healthy smokers (P<0.05). The levels of cleaved caspase-3, MMP-2, MMP-9, TNF-α and IL-1β in the lung tissues from cigarette-treated group were significantly higher than those in control group (P<0.05). The endothelin A receptor antagonist significantly inhibited the levels of cleaved caspase-3, MMP-2, MMP-9, TNF-α and IL-1β (P<0.05). The serum BAP in cigarette-treated group was significantly lower than that in control group (P<0.05). However, endothelin A receptor antagonist significantly increased serum BAP (P<0.05). CONCLUSION:Endothelin-1 may play an important role in the development and progression of COPD through regulating apoptosis, matrix metalloproteinase activity, inflammation and oxidative stress.     

Aquaponics and sustainability: The comparison of two different aquaponic techniques using the Life Cycle Assessment (LCA)

Aquaponics is generally regarded as a sustainable practice, but its environmental burdens were not yet deeply investigated. In this study, Life Cycle Assessment (LCA) was used to assess the environmental impacts of two hypothetical coupled aquaponics systems (CAPS): Raft System (RAFT) and Media-Filled Beds System (MFBS). Rainbow trout (Oncorhynchus mykiss) and lettuce (Lactuca sativa) were considered as cultivated species in both systems. The Simapro^© software V.8.0 was used for calculation. The comparison between the two virtual systems indicated the floating technique as the less impacting one. Even though energy consumption appears to be higher in the floating system, LCA results were markedly influenced by the extensive use of inert materials in MFSB. In both systems, contribution analyses underlined that the main environmental impacts are related to infrastructures, electricity and fish feed. The LCA analyses carried out in this study highlights that the choice of less impacting materials, and the optimization of management practices, should be taken as priorities in order to reduce environmental impacts of this activity.     

大豆花叶病毒侵染性克隆研究进展

大豆花叶病毒(soybean mosaic virus,SMV)是一种株系复杂且不断变化、并对大豆的产量和质量造成恶劣影响的病毒,其严重的致病性受到学者的普遍关注。大豆花叶病毒侵染性克隆技术是研究其致病机理的行之有效的手段。该技术通过病毒侵染获得侵染性cDNA克隆,进一步分析引起症状的相应基因在植株生长过程中的作用机制,由此为SMV相关领域的研究奠定理论基础。本文就大豆花叶病毒侵染性克隆的构建策略和影响因素,以及其应用状况作一综述,以期为大豆花叶病毒的防治提供新的借鉴和思路。     

射流式鱼泵输送草鱼的性能研究

为了分析射流式鱼泵输送草鱼的性能及其损伤因素,文章设计了一台喉管直径为60 mm的射流式鱼泵,开展了草鱼输送实验,并采用高速摄影和计算流体力学方法进行了研究。结果显示,该射流式鱼泵在扬程2.24m时最高草鱼输送能力达918 kg·h~(-1),其所需水功率为2.83 k W。进一步的检测表明,部分实验鱼有鳞片脱落的情况,但未出现游泳异常,解剖后也未发现内脏受损等情况;实验鱼在过泵后呼吸频率及部分血液指标存在明显变化,但在24 h内基本可以恢复。数值模拟和高速摄影方法分析得出,剪切层是造成实验鱼泵内鳞片脱落的主要原因,撞击伤是由内流偏转诱导实验鱼撞击泵内壁面产生的,包含压力梯度在内的水力因素都可能使实验鱼产生应激反应。但由于鱼类在泵内时间极短,上述因素都不会致实验鱼死亡。