刺参肌肉组织cDNA文库的构建

用RNA提取试剂--TRIZOL Reagent提取刺参(Apostichopus japonicus)肌肉组织总RNA,用SMART cDNA Library Construction Kit构建cDNA文库.经测定原始文库滴度达到 3.2×10~6,扩增后文库滴度达到 5.1×10~9,重组率达到96.7%,从扩增文库随机挑取12 个克隆进行PCR 扩增鉴定,结果显示,插入片段大小为0.5～2.5 kb.通过各项指标验证成功构建了刺参肌肉组织cDNA 文库.     

大叶藻全长cDNA文库的构建

以3种不同盐度处理的大叶藻为材料,采用RNA转录本5’末端转换机制(SMART)构建了大叶藻叶片全长cDNA文库,原始文库滴度为8.675×106pfu/mL,重组率为97.19%,插入片段平均长度大于800bp,扩增后的文库滴度达到1.03×109pfu/mL。将部分原始λ噬菌体cDNA文库转化成质粒cDNA文库,PCR检测结果显示文库插入片段集中在750～2000bp之间。随机选取20个单克隆进行测序,其中13条序列包含完整的开放阅读框。结果表明所构建文库容量大,全长比例高,为深入开展大叶藻功能基因研究奠定了基础。     

副溶血弧菌感染的九孔鲍血细胞均一化全长cDNA文库的构建

采用Trizol试剂提取副溶血弧菌感染的九孔鲍血细胞的总RNA,经Oligotex纯化得到mRNA.根据SMART技术原理合成双链cDNA.双链cDNA采用双链特异核酸酶进行cDNA的均一化,构建成九孔鲍血细胞的均一化全长cDNA文库.原始文库的库容为3.4×106 cfu/cm3,重组率为92.3%,扩增后文库的滴度为2.6×1011 cfu/cm3以上.从文库中随机挑取897个克隆,测序获得高质量ESTs814条,其中有23条Contigs; 762条Singlets,Unigenes共785条,冗余率只有3.56%.以上结果说明所构建的文库质量好,完全可以满足后续基因克隆和表达序列标签测序工作的需要.     

南极冰藻谷胱甘肽相关因子的测定

谷胱甘肽系统在清除活性氧和生物保护中发挥重要作用,探讨了南极冰藻胞内谷胱甘肽含量及谷胱甘肽相关酶的活力.采用分光光度法,对24种南极冰藻胞内谷胱甘肽含量、谷胱甘肽合成能力(GPA)、谷胱甘肽还原酶活力等进行测定.测定结果表明,南极蓝藻B-1中谷胱甘肽含量最高;南极衣藻ICE-L和南极硅藻GJ01的谷胱甘肽总产量居前2位;南极冰藻GPA普遍高于常温藻的.南极硅藻GJ01和南极衣藻ICE-L GR活力高于对照组的.培养基的选择表明,f/2培养基适合南极硅藻GJ01的生长,而Provasoli培养基适合南极衣藻ICE-L的生长.可见,南极冰藻成为谷胱甘肽的新来源是有可能的,尤其是南极硅藻GJ01和南极衣藻ICE-L.     

文昌鱼头部cDNA文库的构建

采用cDNA合成技术制备文昌鱼头部cDNA基因文库.以mRNA为模板,用NotI primer-Adaptor为引物,在反转录酶的作用下,合成第一链cDNA,进而合成第二链cDNA.含有EcoRI和NotI粘性末端的双链cDNA在T4DNA连接酶作用下与λgt11 EcoRI/NotI臂相连,包装蛋白包装,得到噬菌体颗粒,即原始的文昌鱼头部cDNA文库.经X-Gal/IPTG板测定, 该文库滴度为7.8×105 pfu/cm3,重组率为70%.cDNA文库可直接应用于目的基因筛选.     

雨生红球藻cDNA表达文库的构建与初步分析

为了筛选雨生红球藻虾青素合成过程中的关键酶基因的反式调节因子基因,以雨生红球藻的绿细胞为材料,提取了高质量的总RNA,并分离纯化了mRNA,经过反转录后的得到cDNA,构建了以λ-ZAPExpress为载体的表达型cDNA文库。经检测,所构建的文库的滴度为5.1×105,重组率为100%。用PCR方法对文库的质量进行了鉴定,文库的平均插入片断的大小为1.7kb。雨生红球藻cDNA表达文库的构建为研究虾青素的代谢工程奠定了基础。     

皱纹盘鲍(Haliotis discushannai Ino)胚胎RNA分离和cDNA文库构建

从皱纹盘鲍胚胎样本中分离RNA并构建了cDNA文库。分别收集孵化8、10和12h的皱纹盘鲍胚胎,用抽滤除菌的海水反复悬浮胚胎,将这3个发育阶段的胚胎样本等量混合后用TRIZOL试剂提取总RNA,将提取物用酚氯仿异戊醇再抽提2次,分离获得高质量的总RNA。从总RNA中分离mRNA,构建了皱纹盘鲍混合胚胎的cDNA文库,未扩增胚胎文库的滴度为5.0×106pfu/ml,重组率为94.12%,插入片段均大于400bp,70.6%克隆的插入片段分布在1000—1500bp之间,扩增后的文库滴度为3.06×109pfu/ml。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

《Acta Oceanologica Sinica》Vol. 33(2014) contents

<正>~~