中国明对虾精氨酸激酶与白斑综合征病毒结构蛋白VP31的作用初探

白斑综合征病毒(white spot syndrome virus,WSSV)是危害对虾的主要病原,给全球水产养殖业带来了巨大经济损失。为研究阻断WSSV的途径,前期研究WSSV与宿主相结合的受体蛋白发现,白斑综合征病毒囊膜蛋白VP31可以与中国明对虾(Fenneropenaeus chinensis)精氨酸激酶(FcAK)发生结合作用。精氨酸激酶(AK)通过调节无脊椎动物体内磷酸精氨酸与三磷酸腺苷(ATP)之间平衡在能量代谢、储存和利用方面具有重要作用。作者通过重组表达的rFcAK与rVP31的far-Western blotting分析,证实两者有结合作用,此外,rFcAK还与WSSV的VP19、VP28等6种结构蛋白有结合作用。双向电泳分析观察到,rFcAK与rVP31的磷酸化反应后,rVP31部分发生pI降低现象,提示rVP31可能发生了磷酸化。生物信息学分析表明VP31存在21个精氨酸残基,FcAK具有12个精氨酸结合位点,这可能为VP31和FcAK的结合活性提供了靶位。为进一步研究WSSV与宿主结合机理及阻断感染的机制提供思路。     

不同辐射背景下大西洋热盐环流下沉区混合层深度变化

基于政府间气候变化专门委员会(Intergovernmental Panel on Climate Change,IPCC)4种最新辐射强迫情景,利用ECHAM5/MPI-OM(European Centre Hamburg Model 5/Max Planck Institute Ocean Model)气候模式输出的1850—2300年逐月混合层深度、海表面温度、海表面盐度数据,分析大西洋热盐环流下沉区混合层深度的变化情况。结果表明:随辐射强迫增加,热盐环流下沉区混合层深度下降,混合层深度振荡周期在格陵兰-冰岛-挪威海(Greenland Sea–Iceland Sea–Norwegian Sea,GIN)海域减小,在拉布拉多海(Labrador Sea,LAB)海域变化不大;与GIN海域相比,LAB海域混合层深度对辐射强迫变化更敏感;两海区温度对混合层深度的影响时间较长,混合层深度对盐度的变化反应迅速;混合层深度变化的主导因素在LAB海域中为盐度,而在GIN海域,低辐射强迫下温度主导混合层深度变化,中高辐射强迫下温度与盐度共同起主导作用。     

2010年夏、秋季胶州湾浮游动物对表层海水中DMS分布的影响

于2010年7~11月对胶州湾夏、秋季浮游动物种类和丰度进行现场调查,并分析讨论了胶州湾夏、秋季浮游动物丰度的水平分布与环境因子(温度、盐度、水深、叶绿素a)和二甲基硫(DMS)、溶解态β-二甲基巯基丙酸内盐(DMSPd)、颗粒态β-二甲基巯基丙酸内盐(DMSPp)的相关性。结果表明,胶州湾浮游动物丰度分布不均匀,8月湾内西部沿岸海域C1站位出现调查期间的动物丰度最大值(656.1ind/m3),最小值(1.492ind/m3)出现在10月胶州湾东北部的A2站位。浮游动物丰度具有明显的季节变化,秋季浮游动物丰度低于夏季浮游动物丰度。浮游动物丰度与盐度、叶绿素a含量、细菌生物量的相关性不明显,2010年10月浮游动物丰度与DMS呈显著正相关(P0.05),11月的浮游动物丰度与DMSPp呈显著正相关(P0.05),其它月份(7、8、9月)的浮游动物丰度与DMS、DMSPd、DMSPp浓度的相关性均不明显。由于浮游动物摄食活动对DMS释放的影响受多种因素的制约,因此浮游动物与DMS的相互作用需要进一步研究。     

三疣梭子蟹HMGR基因的克隆及其在蜕皮中的表达分析

为了研究3-羟基-3-甲基戊二酰辅酶A还原酶(3-hydroxy-3-methyl glutaryl coenzyme A reductase,HMGR)在甲壳动物蜕皮调控中的作用,采用RT-PCR和c DNA末端快速扩增技术(RACE),克隆得到三疣梭子蟹(Portunus trituberculatus)HMGR基因的c DNA序列(Gen Bank登录号:KF280756)。该序列全长2575bp,包括一个53bp的5′端非编码区,一个686bp的3′端非编码区和一个长度为1836bp的开放阅读框,编码611个氨基酸。该氨基酸序列与已公布的美洲海鳌虾HMGR氨基酸序列相比一致性达65%,具有Ⅰ型HMGR保守催化区域、两个HMG-Co A结合基序和两个NADP(H)结合基序。采用实时荧光定量PCR(q RT-PCR)技术,分析三疣梭子蟹HMGR基因的组织差异表达及在蜕皮周期中的表达水平变化,结果表明HMGR基因在三疣梭子蟹大颚器(MO)中的表达量最高,在其它组织中表达量均极低;在三疣梭子蟹蜕皮周期中,大颚器中HMGR基因的表达量自A期至D0亚期升至最高,然后下降,至D4亚期最低。验证了大颚器是三疣梭子蟹合成甲基法尼酯的唯一器官,表明HMGR在三疣梭子蟹蜕皮调控中起着重要作用。     

Effects of pulsed nutrient inputs on phytoplankton assemblage structure and blooms in an enclosed coastal area

The response of phytoplankton assemblage structure to terrestrial nutrient inputs was examined for the Gulf of Kalloni in the Northern Aegean Sea, a productive semi-enclosed coastal marine ecosystem. The study was focused on a typical annual cycle, and emphasis was placed on the comparative analysis between blooms developing after significant nutrient inputs from the watershed, and naturally occurring blooms. Baseline information was collected on a monthly basis from a network of stations located in the oligotrophic open sea and the interior and more productive part of the embayment. Intensive sampling was also carried out along a gradient in the vicinity of a river which was the most important source of freshwater and nutrient input for the Gulf. Phytoplankton assemblage structure was analyzed from 188 samples using diversity indices (Shannon and Average Taxonomic Distinctness), multivariate plotting methods (NMDS), multivariate statistics (PERMANOVA), and canonical correspondence analysis (CCA). Three characteristic assemblages were recognized: (1) an autumn assemblage developed under nutrient depleted conditions, having low diversity due to the dominance of two small diatoms, (2) a winter bloom of the potentially toxic species Pseudo-nitzschia calliantha occurring immediately after a nutrient peak and characterized by very low diversity, and (3) a naturally occurring early summer bloom of centric diatoms with relatively high diversity. The results of the study support the view that moderate nutrient inputs may have a beneficial effect on the functioning of coastal ecosystems, stimulating the taxonomic diversity through the growth of different taxonomic groups and taxa. On the other hand, a sudden pulse of high nutrient concentrations may greatly affect the natural succession of organisms, have a negative effect on the diversity through the dominance of a single species, and can increase the possibility of a harmful algal bloom development.     

螺旋藻多糖对肿瘤细胞生长及Hela细胞早期凋亡作用的实验研究

采用MTT法(四甲基偶氮唑盐比色法)研究了钝顶螺旋藻多糖(PSP)对Hela细胞及HepG2细胞生长的抑制作用。结果表明,随PSP浓度及培养时间的增加,肿瘤细胞存活率逐渐降低,抑制率逐渐增加,以PSP40 mg/L作用72 h最为显著。应用Annexin V/PI双染色流式细胞仪检测了早期Hela细胞凋亡,未经PSP处理的正常Hela细胞凋亡细胞极少,经PSP处理的细胞,凋亡细胞的百分比明显高于正常对照组,其作用随着剂量的增加和时间的延长而增强,具有量效关系和时效关系。结果说明PSP的抗肿瘤机制,除了诱导肿瘤细胞凋亡,还存在细胞毒性等其他机制,是多种机制共同作用的结果。     

Mitigation of Ice-Induced Vibrations for Offshore Platforms Using Tuned Mass Damper

The problems of ice-induced vibration have been noticed and concerned since the 1960s, but it has not been well resolved. One reason is that the dynamic interaction between ice and structure is so complicated that practical ice force model has not been developed. The recent full-scale tests conducted on jacket platforms in the Bohai Sea presented that ice could cause intense vibrations which endanger the facilities on the deck and make discomfort for the crew. In this paper, the strategy of mitigation of ice-induced offshore structure vibration is discussed. Based on field observations and understanding of the interaction between ice and structure, the absorption mitigation method to suppress ice-induced vibration is presented. The numerical simulations were conducted for a simplified model of platform attached with a Tuned Mass Danlper （TMD） under ice force function and ice force time history. The simulation results show that TMD can fa- vorably reduce ice-induced vibrations, therefore, it can be considered to be an alternative approach to utilize. Finally, the application possibilities of utilizing TMDs on other miniature offshore structures in ice-covered areas of marginal oil fields are discussed.     

贻贝(Mytilus edulis)的核型与减数分裂

利用体内注射ＰＨＡ和秋水仙素的方法，以锶和生殖腺为材料，对贻贝ＭｙｔｉｌｕｓｅｄｕｌｉｓＬｉｎｎａｅｕｓ的核型和减数分裂进行了观察分析，结果为，二倍体数２ｎ＝２８，核型为１０ｍ＋１２ｓｍ＋６ｓｔ，ＮＦ＝５０。没有发现异形性染色体，贻贝的减数分裂与其他动物类似，也没有发现异形染色体的特殊行为。     

东海二甲基硫丙酸的分布及其制约因素的初步研究

于１９９４年４月对海水域二甲基硫丙酸浓度进行观测,结合对叶绿素和营养盐的监测结果,分析研究了了ＤＭＳＰ分布及其调控因素。结果表明,ＤＭＳＰ浓度范围为０．１７－５．６６ｎｍｏｌ／Ｌ,最高浓度出现一４１０站。     

蛋白核小球藻在废水污泥中培养的研究

啤酒厂废水污泥中含有一定的营养元素和活性物质。本研究利用废水污泥培养蛋白核小球藻（Chlorellapyrenoidosa）取得了初步结果。将一定比例的活性污泥掺入普通培养液形成混合培养基,其中80：20试验组无论从蛋白核小球藻的生物量还是粗蛋白的含量均与普通培养基的培养产物近似,具有实践意义。结果表明,混合培养基培养某些藻类,不仅降低了养殖成本,还可净化环境,为废水污泥用于藻类养殖开辟了一条新途径。