地高辛标记核酸探针的标记方法及其在食用菌研究领域的应用

综述了非放射性地高辛（DIG）标记系统的原理和主要特点，介绍了地高辛标记核酸探针的主要标记方法，影响探针标记方法选择的因素，标记探针的显色检测方法及其在食用菌研究领域的应用。     

Bed scouring downstream of hydraulic structures under steady flow conditions: Experimental analysis of space and time scales and implications for mathematical modeling

Sediment transport and bed deformation in alluvial rivers are space and time dependent. The knowledge of the space and time scales can be helpful for the definition of predictive procedures of an alluvial reach response to changing boundary conditions. In this work, attention is paid to scouring process occurring downstream of the rigid basement of a hydraulic structure. The analysis is focused on transient bed profiles which are determined, under steady flow conditions, by a decrease of the upstream sediment transport rate. In particular, the paper is aimed at improving understanding of the space and time scales required by the alluvial system to reach the equilibrium conditions. For this purpose, movable-bed runs are carried out in a straight laboratory channel, for two values of the water discharge. During each run, the longitudinal bed profiles are measured at different times. Based on experimental data, spatial scale factors of the bed scouring and of the bed load transport to reach the equilibrium conditions are defined. Particularly, it is found that the scour length varies especially during the first evolution phase and then it oscillates around of a mean value that is about 40% of the channel reach interested by the phenomenon under consideration; an expression is found for the adaptation coefficient which allows the estimation of the spatial delay of the bed load transport rate. Using both the collected data and literature data an expression defining the time scale of scouring is deducted. According to this expression the non-dimensional time scale is related to Shields parameter through an exponential law. Then, by the help of a 1-D numerical model previously developed by the writer, the implications for choosing the spatial and temporal resolutions, on which numerical results depend significantly, are shortly discussed. The results show that the time and space scales, which represent physical constraints of the spatial and temporal resolutions, need to be properly defined in order to simulate the scouring process evolution.     

一株类NADC30猪繁殖与呼吸综合征病毒的全基因组序列分析

为监测猪繁殖与呼吸综合征病毒(PRRSV)流行毒株的基因变异情况,采用RT-PCR方法对某猪场疑似患有猪繁殖与呼吸综合征(PRRS)的猪组织样品进行鉴定,测序获得全基因,并对该毒株的NSP2基因缺失特征同源性和遗传进化及重组情况进行分析。结果显示:该猪场感染猪体的病原体为PRRSV,该毒株被命名为180404-2fei;180404-2fei毒株的NSP2区存在131(111+1+19)个氨基酸的不连续缺失,与报道的类NADC30毒株缺失特征一致;180404-2fei的NSP2基因与NADC30毒株核苷酸和氨基酸同源性分别为92.2%和90.1%,180404-2fei毒株的ORF5基因与NADC30的核苷酸及氨基酸序列同源性分别为93.5%和92.0%;遗传进化和重组分析结果表明,180404-2fei毒株属于NADC30-Like亚群,可能是由NADC30与HP-PRRSV重组而来。本研究通过对一株类NADC30 PRRSV的全基因组序列进行分析,为研究PRRSV的遗传变异和PRRS的防控提供了参考依据。     

创新实验班“分子生物学”教学改革与实践

分子生物学是生命科学最重要的基础课程,对培养生命科学类研究型拔尖人才起着关键作用。从"创新实验班"入手,浓缩讲授内容,注重理论与理论发现的整合,增设学生主题讨论,开展研究热点追踪,采用说课、启发研讨、探究讨论、"辩论性分子秀"等互动教学方式,通过改革实验课的开设与实验考核及建立多元的评价机制,激发了学生学习的浓厚兴趣,营造了独立思考、自由探索、勇于创新的良好氛围,取得很好的教学效果。     

枸杞多糖的提取分离及其组成研究

对枸杞多糖的提取分离及其组成进行了研究,结果表明:枸杞经氯仿-甲醇脱脂,水提醇沉,乙醇、丙酮和乙醚洗涤干燥,双氧水脱色,savage法除蛋白后可得枸杞多糖;高效液相色谱测定枸杞多糖分子量为:73 950～138 090 Da;枸杞多糖中单糖分别有葡萄糖、阿拉伯糖、鼠李糖、半乳糖、木糖和甘露糖,其中含量较多的是葡萄糖、阿拉伯糖和半乳糖,其他单糖含量较低。     

分子水平上的适应进化

从分子进化的概念、分子进化中性论和生物大分子的适应进化(大分子结构适应方面的进化和适应进化的机制方面)论述了分子水平上适应进化的方式及其特点。     

鲮鱼鱼皮胶原蛋白酶解物分子量分布与抗氧化性的研究(英文)

[目的]为了研究鲮鱼鱼皮胶原蛋白水解物的分子量的分布及抗氧化活性。[方法]分子量分布采用分子排阻色谱法和基质辅助激光解吸附飞行时间质谱(MALDI-TOF-MS),鱼皮用碱性蛋白酶2709处理。[结果]最佳水解条件为:pH 10.0、反应温度55℃、底物浓度为80 g/L、酶和底物比4%,水解时间3 h。两种方法分析水解产物的相对分子质量分布范围为400~1 800 Da,大多数胶原蛋白短肽的分子量在1 400 Da以下。[结论]结果表明,鱼皮水解物是一种潜在的抗氧化物。     

家蚕基因组中的分子标记遗传图谱

遗传标记既是基因组研究的重要内容，又是构建遗传图谱、研究生物多样性、育种、基因定位与克隆等的基因。目前，已有多项分子标记技术用于家蚕基因组的研究，并构建了多种分子标记遗传图谱，包括限制性酶切片段长度多态性（简称RFLP）、DNA随机扩增多态性（简称RAPD）、扩增片段长度多态性（简称AFLP）、简单重复序列PCR（简称SSR－PCR）等。本文就分子标记技术构建的家蚕基因组分子标记遗传图谱进行了讨论。     

Quantifying diversity losses due to selection for scrapie resistance in three endangered Spanish sheep breeds using microsatellite information

The effect of selection for scrapie resistance on genetic variability in three endangered Spanish sheep breeds (Colmenareña, Mallorquina and Rubia de El Molar) was studied using two different criteria for quantifying contributions to genetic variability: (a) molecular coancestry or genetic identity; and (b) average number of alleles per locus or allelic richness. A total of 236 (81 Colmenareña, 76 Mallorquina and 79 Rubia de El Molar) individuals were genotyped for the PrP gene and for 22 microsatellite markers. The analyses assumed a selective policy aimed at the elimination of the VRQ allele and the reduction of the frequency of the ARQ/ARQ genotype. These goals are approached by rejecting for breeding those individuals with the highest susceptibility for scrapie (risk groups R4 and R5) in a genetic scenario with no previous selection programmes considering the PrP gene polymorphism carried out. When all the individuals classified into risk groups R4 and R5 were removed from the dataset, the total molecular coancestry slightly increased in the Colmenareña breed illustrating that the carriers of undesirable PrP genotypes are not essential to maintain its overall gene diversity. When the allelic richness was considered, the removal of the R4 and R5 individuals gave high losses in the Rubia de El Molar breed. The analyses carried out considering the sex of the individuals informed that most increases in genetic identity in the Colmenareña breed resulted from the removal of the R4 and R5 males while in the Mallorquina breed resulted from the removal of the undesirable females. Losses of diversity in the Rubia de El Molar breed were basically independent of the sex of the individuals due to the balanced contributions to diversity of both sexes. As a general recommendation, not all the individuals of undesirable risk groups should be rejected for reproduction at the same time to avoid irretrievable loses of genetic diversity but according to the sex of the individuals.     

水稻白叶枯病抗性研究进展

白叶枯病是世界水稻重要病害之一,且已成为研究植物和病原菌互作的模式,对该病的研究对其它病害有借鉴意义。目前已鉴定出29个抗白叶枯病基因,其中17个基因被定位到染色体上,4个基因已被克隆,在这些工作的基础上,已通过分子标记辅助选择和转基因方法育成了一些抗病新品系,展示了水稻抗白叶枯病分子育种的广阔前景。