猪一般型生殖道放线菌的分离鉴定与系统进化分析

2007年4月, 从患有化脓性肺炎、化脓性关节炎和心内膜炎的8周龄病死仔猪内脏器官中分离到一株细菌, 对其进行了种属关系鉴定、致病性及药物敏感性等研究。首先从表型特征和生化特性方面进行鉴定, 然后应用分子技术对其16S rDNA进行测序分析, 最后进行了动物实验和药物敏感性实验。该细菌表型特征和生化特性表明其与生殖道放线杆菌(A. hyovaginalis)非常相似; 对16S rDNA测序结果分析发现其与A. hyovaginalis III群菌株同源性高达99.2%, 系统进化分析也表明分离株与A. hyovaginalis III群菌株亲缘关系最近; 对小白鼠具有较强的致病性; 对红 霉素、庆大霉素和阿米卡星等药物高度敏感。因此, 证实分离菌株为有致病性的A. hyovaginalis III型。     

裂解型布鲁氏菌噬菌体的分子特征研究

目的:研究布鲁氏茵噬茵体Tb(Tbilisi)的形态学和分子生物学特征.方法:采用透射电镜观察噬茵体颗粒形态,双层琼脂法观察噬斑形态,梯度密度离心纯化噬茵体颗粒,提取噬茵体基因组,采用多种限制性内切酶(S1,DNase I,RNase A,BamHI)对基因组进行酶切琼脂糖凝胶电泳,SDS-PAGE观察噬茵体颗粒全蛋白片段.结果:Tb噬茵体电镜下显示头部直径为57±2nm,短尾(32±3mm长),分类学属于短尾噬茵体科.培养48小时后显示清晰噬斑,大小为2～3mm.核酸结构分析均表明Tb噬菌体基因组为线性dsDNA分子.基因组DNA经限制性内切酶BamHI酶切产生2条清晰条带,分子量在34.5kb左右.SDS-PAGE全蛋白电泳显示Tb噬菌体含有9条主要结构蛋白.结论:该研究证实了Tb噬菌体属于短尾病毒科噬菌体,对宿主菌存在裂解效应并产生2～3mm清晰透亮形态的噬斑,基因组为dsDNA分子,全蛋白包含9条主要的结构蛋白.该研究结果为布鲁氏菌噬菌体的分子水平的研究提供了新的研究基础.     

PMSG、E_2、PGF_(2α)和hCG组合处理对初情前蓝狐卵巢和子宫的影响

为了完善提高狐狸繁殖效率的超排技术,探讨了用PMSG、E2、PGF2α和hCG的不同组合处理对诱发初情前雌性蓝狐发情及其对卵巢和子宫发育的影响.EPP组(E2、PMSG和PGF2α组合)和EPPh组(E2、PMSG、PGF2α和hCG组合)分别有2只和3只发情,而对照组未见发情;EPP和EPPh组卵巢指数和有腔卵泡百分率显著高于对照组(P<0.05),而初级卵泡所占百分率则显著低于对照组.此外,EPPh组次级卵泡所占百分率与对照组相比显著降低(P<0.05);当用EPP和EPPh法处理雌性蓝狐后,子宫指数、子宫壁和子宫内膜厚度显著高于对照组(P<0.05).结果 表明,EPP和EPPh处理不仅具有诱发雌性蓝狐发情的功效,而且能够提高初情前雌性蓝狐卵巢指数和增加有腔卵泡数量.     

MicroRNA引起mRNA降解关键核酸酶CAF1和POP2的生物进化分析

MicroRNA(miRNA)参与调控高等真核生物中三分之一以上基因的表达,其中核酸酶CAF1(CCR4-associated factor 1)及其同源基因POP2在miRNA引发的mRNA 3′端多聚腺苷酸(poly(A))的脱腺苷酸化过程中起了关键作用.通过实时定量RT-PCR的方法检测了小鼠各个组织中CAF1和POP2的相对表达情况,发现CAF1和POP2的组织分布特征不同.大多数组织中CAF1的表达水平明显高于POP2,并且组织间差异很大,特别是在大脑、小脑以及睾丸组织中CAF1的表达量很高,而POP2的表达量和变化幅度都较低.蛋白质序列比对发现,CAF1和POP2是一类进化过程中高度保守的核酸外切酶,在酵母、线虫、果蝇和尾索动物代表物种海鞘中都只存在单一基因,而进化到鱼类后产生了两个同源基因——CAF1和POP2,其中CAF1的氨基酸序列保守性较POP2更高,更加接近于原始的单一序列.CAF1和POP2这一对同源基因氨基酸序列的主要差别在蛋白质的C端.鱼类中POP2的C端序列同CAF1的序列较为接近,而在爬行动物之后POP2产生了与CAF1具有明显差异的C端序列,并逐渐趋于稳定.我们的分析结果同已有的功能研究一致,表明可能在miRNA产生后的进化过程中产生了CAF1和POP2两个同源基因,其中CAF1主要担负miRNA调控mRNA脱腺苷酸化的功能,而POP2可能主要参与其它不同的调控作用。     

The European carbon balance. Part 2: croplands

We estimated the long‐term carbon balance [net biome production (NBP)] of European (EU‐25) croplands and its component fluxes, over the last two decades. Net primary production (NPP) estimates, from different data sources ranged between 490 and 846 gC m^?2 yr^?1, and mostly reflect uncertainties in allocation, and in cropland area when using yield statistics. Inventories of soil C change over arable lands may be the most reliable source of information on NBP, but inventories lack full and harmonized coverage of EU‐25. From a compilation of inventories we infer a mean loss of soil C amounting to 17 g m^?2 yr^?1. In addition, three process‐based models, driven by historical climate and evolving agricultural technology, estimate a small sink of 15 g C m^?2 yr^?1 or a small source of 7.6 g C m^?2 yr^?1. Neither the soil C inventory data, nor the process model results support the previous European‐scale NBP estimate by Janssens and colleagues of a large soil C loss of 90 ± 50 gC m^?2 yr^?1. Discrepancy between measured and modeled NBP is caused by erosion which is not inventoried, and the burning of harvest residues which is not modeled. When correcting the inventory NBP for the erosion flux, and the modeled NBP for agricultural fire losses, the discrepancy is reduced, and cropland NBP ranges between ?8.3 ± 13 and ?13 ± 33 g C m^?2 yr^?1 from the mean of the models and inventories, respectively. The mean nitrous oxide (N₂O) flux estimates ranges between 32 and 37 g C Eq m^?2 yr^?1, which nearly doubles the CO₂ losses. European croplands act as small CH₄ sink of 3.3 g C Eq m^?2 yr^?1. Considering ecosystem CO₂, N₂O and CH₄ fluxes provides for the net greenhouse gas balance a net source of 42–47 g C Eq m^?2 yr^?1. Intensifying agriculture in Eastern Europe to the same level Western Europe amounts is expected to result in a near doubling of the N₂O emissions in Eastern Europe. N₂O emissions will then become the main source of concern for the impact of European agriculture on climate.     

The European carbon balance. Part 1: fossil fuel emissions

We analyzed the magnitude, the trends and the uncertainties of fossil‐fuel CO₂ emissions in the European Union 25 member states (hereafter EU‐25), based on emission inventories from energy‐use statistics. The stability of emissions during the past decade at EU‐25 scale masks decreasing trends in some regions, offset by increasing trends elsewhere. In the recent 4 years, the new Eastern EU‐25 member states have experienced an increase in emissions, reversing after a decade‐long decreasing trend. Mediterranean and Nordic countries have also experienced a strong acceleration in emissions. In Germany, France and United Kingdom, the stability of emissions is due to the decrease in the industry sector, offset by an increase in the transportation sector. When four different inventories models are compared, we show that the between‐models uncertainty is as large as 19% of the mean for EU‐25, and even bigger for individual countries. Accurate accounting for fossil CO₂ emissions depends on a clear understanding of system boundaries, i.e. emitting activities included in the accounting. We found that the largest source of errors between inventories is the use of distinct systems boundaries (e.g. counting or not bunker fuels, cement manufacturing, nonenergy products). Once these inconsistencies are corrected, the between‐models uncertainty can be reduced down to 7% at EU‐25 scale. The uncertainty of emissions at smaller spatial scales than the country scale was analyzed by comparing two emission maps based upon distinct economic and demographic activities. A number of spatial and temporal biases have been found among the two maps, indicating a significant increase in uncertainties when increasing the resolution at scales finer than ≈200 km. At 100 km resolution, for example, the uncertainty of regional emissions is estimated to be 60 g C m^?2 yr^?1, up to 50% of the mean. The uncertainty on regional fossil‐fuel CO₂ fluxes to the atmosphere could be reduced by making accurate ¹⁴C measurements in atmospheric CO₂, and by combining them with transport models.     

离体条件下TDZ对解除北五味子种子休眠的影响

以深度休眠的北五味子种子为材料,研究了离体条件下,种皮、胚乳因素对北五味子种子休眠的影响;建立了离体条件下,使用TDZ有效解除北五味子种子休眠的方法;并对北五味子种子解除休眠过程中过氧化物酶和过氧化氢酶活性变化规律进行分析.结果表明,(1)种皮和胚乳因素是引起北五味子种子休眠的主要因素,种皮和胚乳对北五味子种子的萌发具有不同程度的抑制作用;(2)MS培养基中添加0.02 mg·L-1 TDZ能有效解除北五味子种子休眠,可使第30天的发芽率达到90.0%,显著缩短北五味子种子休眠时间;(3)随着北五味子种子休眠被解除,过氧化物酶和过氧化氢酶活性均呈明显的增加趋势.     

黄鼬在吉林环长白山旅游公路路域活动的调查研究

2008年11～12月,采用样线法对环长白山旅游公路改扩建工程全线路域200 m范围内黄鼬活动情况进行了3次调查.调查结果显示:K10～K45路段黄鼬穿越公路较多;黄鼬穿越公路频率与路域植被类型和雪被深度有密切的关系;黄鼬已经开始利用涵洞穿越公路;公路对黄鼬具有吸引效应,影响域范围约为50 m.为此提出了相应的保护对策.     

避暗反应测定大鼠学习记忆功能方法的探讨

目的 为了提高避暗反应测定动物学习记忆功能的敏感性,本实验对三种实验及统计方法进行了评价。方法 采用IBO致基底前脑胆碱能神经元损伤模型和东莨菪碱所致的记忆障碍模型,对单次简单测试法、多次简单测试法和多次记分测试法的敏感性进行了比较。结果 对于基底前脑损伤模型,单次简单测试法的潜伏期学习记忆指标无法显示出模型组与对照组之间的差异。多次简单测试法两种指标均能显示出显著性差异,且较多次记分测试法的指标差异的显著性高。对于东莨菪碱致痴呆模型,也有同样的效果。结论 多次简单测试法更能敏感地反映动物的学习记忆功能。     

大剂量地塞米松快速高效诱导巨噬细胞凋亡

运用透射电镜、DNA琼脂糖凝胶电泳、流式细胞术、原位末端标记法(TUNEL)染色等技术,检测了大剂量地塞米松处理小鼠腹腔巨噬细胞的各种变化.结果显示,大剂量地塞米松处理的巨噬细胞发生胞体皱缩、染色质凝聚、胞质浓缩;TUNEL染色呈阳性;0.5 h后DNA凝胶电泳即呈梯状条带;流式细胞术作周期分析出现凋亡峰等明显的凋亡特征.并且随处理时间延长凋亡率升高.结果表明,大剂量地塞米松快速、高效诱导小鼠腹腔巨噬细胞凋亡.