微生物制剂在淡水养殖中的应用及前景

报道了活体微生物、微生物代谢产物、疫苗等微生物制剂在淡水养殖中的应用,从水质调节、疾病防治,作为饲料和饲料添加剂等几个方面探讨了微生物制剂在淡水养殖中的应用前景.     

基于环境海洋学的渤海湾环境分析

人类的活动,使渤海的污染日趋严重,生态环境急剧恶化,赤潮频频发生,渔类资源渐趋枯竭。本文根据现有的数据从环境海洋学的角度对渤海的环境现状进行分析并提出了治理对策。     

Progress of regional oceanography study associated with western boundary current in the South China Sea

Recent progress of physical oceanography in the South China Sea (SCS) associated with the western boundary current (WBC) and eddies is reviewed in this paper. It includes Argo observations of the WBC, eddy detection in the WBC based on satellite images, cross-continental shelf exchange in the WBC, eddy-current interaction, interannual variability of the WBC, air-sea interaction, the SCS throughflow (SCSTF), among others. The WBC in the SCS is strong, and its structure, variability and dynamic processes on seasonal and interannual time scales are yet to be fully understood. In this paper, we summarize progresses on the variability of the WBC, eddy-current interaction, air-sea interaction, and the SCSTF achieved in the past few years. Firstly, using the drifting buoy observations, we point out that the WBC becomes stronger and narrower after it reaches the central Vietnam coast. The possible mechanisms influencing the ocean circulation in the northern SCS are discussed, and the dynamic mechanisms that induce the countercurrent in the region of northern branch of WBC in winter are also studied quantitatively using momentum balance. The geostropic component of the WBC was diagnosed using the ship observation along 18°N, and we found that the WBC changed significantly on interannual time scale. Secondly, using the ship observations, two anti-cyclonic eddies in the winter of 2003/2004 in the northern SCS, and three anti-cyclonic eddies in the summer of 2007 along 18°N were studied. The results show that the two anti-cyclonic eddies can propagate southwestward along the continental shelf at the speed of first Rossby wave (～0.1 ms-1 ) in winter, and the interaction between the three anti-cyclonic eddies in summer and the WBC in the SCS is preliminarily revealed. Eddies on the continental shelf of northern SCS propagated southeastward with a maximum speed of 0.09 ms-1 , and those to the east of Vietnam coast had the largest kinetic energy, both of which imply strong interaction between eddy activity and WBC in the SCS. Thirdly, strong intraseasonal variability (ISV) of sea surface temperature (SST) near the WBC regions was found, and the ISV signal of SST in winter weakens the ISV signal of latent heat flux by 20%. Fourthly, the long-term change of SCSTF volume transport and its connection with the ocean circulation in the Pacific were discussed.     

“遗传印记”现象的研究

“遗传印记”现象是由于子代体内来自父母双方的等位基因一方表达、另一方沉默造成的,对该现象的研究是分子遗传学研究的新兴领域之一。目前,通过一些研究方法,对“遗传印记”的分子机制已有一定的认识,随着对“遗传印记”研究的逐渐深入,必将深化人们对遗传和生命本质的认识。     

台中-厦门直航航路的海象特性

以台湾海峡为范围,收集台中、厦门航路的卫星观测数据,建立风速与浪高对应关系.该航路于东北季风时期,海象为5～7级风、5～6级浪,较西南季风时期明显高出二级,属恶劣航行季节;全年中335天浪高低于4m,若以4m浪高作为耐波极限,建议选择5000 t以上钢体结构船作为适航船舶.     

黄连木叶片基因组DNA提取方法

黄连木叶片中酚类化合物、色素、多糖和其它次生代谢物质含量较高,这给黄连木基因组DNA提取带来困难。为了从黄连木叶片中提取高质量基因组DNA,本文运用CTAB法和改良CTAB法提取黄连木基因组DNA,通过定性、定量及PCR分析检测所提取DNA的质量。结果表明:改良CTAB法提取的DNA电泳条带清晰无RNA等污染,OD260和OD280比值在1.8左右,RAPD扩增条带清晰、无弥散现象、亮度均一。说明改良CTAB法提取的DNA纯度较高,适用于PCR扩增反应。     

基因组原位杂交中探针长度的优化

本文对普通野生稻Oryza rufipogon DNA的提取、纯化到最后将DNA剪切成300-500bp的整个过程进行了阐述．同时因为鲑鱼精DNA的G、C含量比较均匀，具有一定的剪切代表性，也对其进行了长度剪切，用来和普通野生稻Oryza rufipogon DNA进行比较，以得出其煮沸时间和剪切长度的关系是否具有普遍性，结果初步验证了普通野生稻Oryza rufipogon DNA的煮沸时间和长度变化的关系与鲑鱼精DNA的煮沸时间和长度变化的关系有很大差别，说明普通野生稻Oryza rutlpogon DNA的煮沸时间和长度变化的关系没有普遍性，而只能说明普通野生稻Oryza rufipogon DNA本身的特性。     

Genomic and functional adaptation in surface ocean planktonic prokaryotes

The understanding of marine microbial ecology and metabolism has been hampered by the paucity of sequenced reference genomes. To this end, we report the sequencing of 137 diverse marine isolates collected from around the world. We analysed these sequences, along with previously published marine prokaryotic genomes, in the context of marine metagenomic data, to gain insights into the ecology of the surface ocean prokaryotic picoplankton (0.1-3.0?μm size range). The results suggest that the sequenced genomes define two microbial groups: one composed of only a few taxa that are nearly always abundant in picoplanktonic communities, and the other consisting of many microbial taxa that are rarely abundant. The genomic content of the second group suggests that these microbes are capable of slow growth and survival in energy-limited environments, and rapid growth in energy-rich environments. By contrast, the abundant and cosmopolitan picoplanktonic prokaryotes for which there is genomic representation have smaller genomes, are probably capable of only slow growth and seem to be relatively unable to sense or rapidly acclimate to energy-rich conditions. Their genomic features also lead us to propose that one method used to avoid predation by viruses and/or bacterivores is by means of slow growth and the maintenance of low biomass.     

家兔基因文库的建立

根据鸟枪法克隆基因的原则，建立了家兔总ＤＮＡ文库。为适应同位素标记探针法克隆筛选方法，建立了以人噬菌体为载体的文库。每个重组子携家兔基因组ＤＮＡ平均２０ｋｂ，共获重组噬菌体达１０＾６。以人生长激素ｃＤＮＡ为探针，采用噬菌斑原位杂交、斑点杂交和Ｓｏｕｔｈｅｒｎ杂交等操作，对以噬菌体为载体的文库进行了筛选和有效性验证。结果表明：（１）人生长激素与兔生长激素的ＤＮＡ存在相当的同源性，以人生长激素ｃＤＮＡ     

Genomic rearrangements correlated with antigenic variation in Trypanosoma brucei

The capacity of African trypanosomes to express sequentially a large repertoire of different surface antigens during an infection enables the parasite to evade the immune response of its host, and makes attempts to produce a vaccine against the disease difficult. It is evident that point mutations cannot account for antigen diversity. Variable antigens like immunoglobulins are derived from an extensive family of genes of which only one is expressed in a given cell. As somatic tic recombination is involved in the immunoglobulin gene system, this similarity prompted us to search for somatic rearrangements in trypanosome variable antigen genes. We have constructed a recombinant plasmid containing approximately half the DNA sequence coding for a Trypanosoma brucei variable antigen and hybridised the inserted sequences to various restriction enzyme digests of nuclear DNA from different trypanosome clones. Differences in the sizes of restriction tion fragments hybridising to the inserted variable antigen coding sequence show altered positions of enzyme sites relative to this sequence, indicating different arrangements of DNA sequences around this gene in different trypanosome clones.