Phaeocystis globosa与Phaeocystis antarctica叶绿体psbA基因的比较   总被引：3，自引：0，他引：3       下载免费PDF全文

杨泽民  章群  谢数涛  韩博平  吕颂辉  Hodgkiss 《海洋科学》2005,29(1):24-28

测定了2株球形棕囊藻Phaeocystis globosa P1、P2的psbA基因序列。发现得到的2个序列完全相同。以P2序列对比分析了P．globosa和P．antarctica的psbA基因在DNA序列、氮基酸序列和RNA二级结构上的差异性，发现2种棕囊藻psbA基因DNA序列和氨基酸序列非常保守，无插入／缺失，其核苷酸和氨基酸变异率分别为1．88％和1．13％。与核基因核苷酸的碱基替换不同，psbA基因核苷酸的碱基替换主要发生在密码子的第1位上。且不引起氨基酸的变化，引起氨基酸变化的碱基替换都发生在密码子的第2位和第3位上。在RNA二级结构上两序列的1～4茎环结构完全相同，表现出明显的棕囊藻属的特异性，其它结构区域差异较大。种间差异表现明显。由于psbA基因DNA序列和氨基酸序列非常保守，可能不适宜棕囊藻属的系统发育分析。但其RNA二级结构可能对于棕囊藻的分子分类有一定的参考价值。  相似文献   

日本(虫寻)和底栖短桨蟹线粒体DNA 12SrRNA基因序列的初步研究   总被引：6，自引：1，他引：6  

高天翔  张秀梅  渡边精一  伏屋玲子 《中国海洋大学学报(自然科学版)》2004,34(1):43-47

以相应引物对日本和底栖短桨蟹的线粒体 DNA1 2 S r RNA基因片段进行了 PCR扩增和序列测定 ,分析比较了 2种间序列差异。结果表明 :日本 1 2 S r RNA基因片段长度为 41 4 bp,底栖短桨蟹为 41 5bp,2种的 A,T,G,C含量分别为 1 51 bp(36.47% ) ,1 53bp(36.96% ) ,43bp(1 0 .39% ) ,67bp(1 6.1 8% )和 1 50 bp(36.1 4 % ) ,1 55bp(37.35% ) ,44bp(1 0 .60 % ) ,66bp(1 5.90 % )。 2种间共出现了 3个碱基的缺失 /插入和 38bp的序列差异 ,其碱基转换与碱基颠换比约为 2 .1 7。  相似文献   

合浦珠母贝26S蛋白酶体S4,S7亚基基因片段的分离与分析     

姜铁民  张勇  黄洁  谢莉萍  吴移谋  张荣庆 《海洋科学》2003,27(4):28-34

26S蛋白酶体是真核生物中一种具有ATP依赖性的蛋白酶复合体,主要通过泛肽途径选择性降解细胞内与代谢调控、细胞周期有关的功能蛋白及异常蛋白,参与多种细胞活动的调控过程。26S蛋白酶体由具有催化活性的20S亚复合体和一个具有调节作用的19S亚复合体组成,其中19S亚复合体中的ATP酶亚基是调节26S蛋白酶体活性的重要组件。本通过简并引物PCR手段,从软体动物合浦珠母贝(Pinctada fucata)中扩增到参与构成19S亚复合体的S4和S7(MSS1)两个亚基的基因片段。这两个基因片段所编码的ATP酶组件包含有Gx4GKT,DEID,SAT和H／QRxGRxxR等26S蛋白酶体ATP酶亚基的共同功能基序。这是首次在软体动物中报道26S蛋白酶体的ATP酶亚基基因序列,为研究软体动物中26S蛋白酶体的结构与功能奠定了分子基础。  相似文献   

Glaciomarine sedimentation and palaeo-glacial setting of Maxwell Bay and its tributary embayment, Marian Cove, South Shetland Islands, West Antarctica     

Ho Il Yoon  Myung Woo Han  Byong-Kwon Park  Jae-Kyung Oh  Soon-Keun Chang 《Marine Geology》1997,140(3-4):265-282

High-resolution (3.5 kHz and multi-channel) seismic profiles and piston cores were collected from Maxwell Bay and its tributary embayment, Marian Cove, in the South Shetland Islands, Antarctica, during the Korea Antarctic Research Program (1992/93 and 1995/96) to elucidate the glaciomarine sedimentation processes and recent glacial history of the area. Seismic data from Maxwell Bay reveal a rugged bay margin and flattened basin floor covered with well-stratified hemipelagic muds. On the base-of-slope, acoustically transparent debris flows occur, indicating downslope resedimentation of glaciomarine sediments. Despite the subpolar and ice-proximal settings of Marian Cove, the seafloor is highly rugged with a thin sediment drape, suggesting that much of the area has been recently eroded by glaciers. Sediment cores from the cove penetrated three distinct fining-upward lithofacies: (1) basal till in the lower part of the core, accumulated just seaward of the grounding line of the tidewater glacier; (2) interlaminated sand and mud in the middle part, deposited in ice-proximal zone by a combination of episodic subglacial meltwater inflow and iceberg dumping; and (3) pebbly mud in the upper part, deposited in ice-distal zone by both surface meltwater plume and ice-rafting from the glacier front. A reconstruction of the glacial history of these areas since the late glacial maximum shows an ice sheet filling Maxwell Bay in late Wisconsin time and grounding of the tidewater glacier in Marian Cove until about 1300 yr BP.  相似文献   

Microbial Diversity in Nankai Trough Sediments at a Depth of 3,843 m   总被引：6，自引：0，他引：6  

Lina Li  Jean Guenzennec  Peter Nichols  Pierre Henry  Miki Yanagibayashi  Chiaki Kato 《Journal of Oceanography》1999,55(5):635-642

Dense populations of bivalves, primarily Calyptogena sp., were observed at cold seeps of the Nankai Trough. Bacterial input to the sediment was estimated through determination of phospholipid ester-linked fatty acid (PLFA) and DNA profiles. Results indicated a bacterial biomass of 10⁹ cells (g dry wt)^-1 while individual fatty acid profiles revealed a predominance of monounsaturated fatty acids, mainly 18:1 isomers. The presence of these fatty acids can be interpreted to reflect a response to low temperature and a predominance of psychrophilic bacteria. DNA fragments encoding bacterial ribosomal RNA small-subunit sequences (16S rDNA) were amplified by the polymerase chain reaction method using DNA extracted directly from the sediment samples. From the sequencing results, at least 19 kinds of bacterial 16S rDNAs related to mostly the Proteobacteria and a few gram-positive bacteria were identified. These results suggest that the bacterial community in the Nankai Trough sediments consists of mainly bacteria belonging to the Proteobacteria , , and subdivisions. Bacteria belonging to the and subdivisions, which are known to include epibiont and sulfate reducing bacteria, respectively, were mostly detected in the sediment obtained from inside the area of the Calyptogena community, and the -Proteobacteria may function to supply reduced sulfur to bacterial endosymbionts of Calyptogena.  相似文献   

牙鲆种群动态及其资源管理     

朱鑫华 《海洋与湖沼》1992,23(3):270-279

本文根据1980—1986年间鱼类生物学参数测定,结合体长分布资料的模拟分析,研究黄、渤海区牙鲆种群年龄结构、死亡动态以及在不同年龄和死亡率条件下世代资源生物量变化的规律。模型分析结果表明,当F=1.0和t_c=6.0a时,单位补充量最大群体产量为1492g。由此认为,现阶段牙鲆资源利用的最佳策略是通过增殖放流,增加资源补充;同时应适当控制捕捞压力,减少渔具对幼鱼资源的破坏并增设繁殖保护区,以追求最大持续产量。  相似文献   

壳聚糖酶高产菌株的筛选和发酵条件的研究   总被引：6，自引：0，他引：6  

孙玉英  韩宝芹  刘万顺  张继泉  姚如永  彭睿 《中国海洋大学学报(自然科学版)》2007,37(2):266-272

从采集的土样中分离到1株产壳聚糖酶能力较强的菌株OU01,并对OU01进行了16S rDNA序列、形态及生理生化鉴定分析。16S rDNA序列分析表明该菌属于微杆菌属;该菌的形态特征与生理生化鉴定结果表明该菌与Microbacteriumsp.的相似性最高;因此将其初步鉴定为微杆菌属(Microbacterium)。同时对该菌的发酵条件进行了初步研究:该菌的最适培养基组成为(g/L):chitosan 10,(NH4)2SO420,MgSO4.7H2O 1.3,K2HPO4.3H2O 1.4,Glucose 1,Yeast extract 3,NaCl 5,起始pH=6.30。最适发酵温度为30℃,最佳发酵时间为96 h,在上述最优条件下,该菌株产酶达到118 U/mL。Microbacteri-umsp.OU01菌株为壳聚糖酶的研究和应用提供了新的来源。  相似文献   

Phylogenetic analysis of Pectinidae(Bivalvia) based on the ribosomal DNA internal transcribed spacer region     

HUANG Xiaoting  BI Ke  HU Jingjie  HU Xiaoli  BAO Zhenmin 《海洋学报(英文版)》2007,26(6):83-90

The ribosomal DNA internal transcribed spacer (ITS) region is a useful genomic region for understanding evolutionary and genetic relationships. In the current study, the molecular phylogenetic analysis of Pectinidae (Mollusca: Bivalvia) was performed using the nucleotide sequences of the nuclear ITS region in nine species of this family. The sequences were obtained from the scallop species Argopecten irradians, Mizuhopecten yessoensis, Amusium pleuronectes and Mimachlamys nobilis, and compared with the published sequences of Aequipecten opercularis, Chlamys farreri, C. distorta, M. varia, Pecten maximus, and an outgroup species Perna viridis. The molecular phylogenetic tree was constructed by the neighbor-joining and maximum parsimony methods. Phylogenetic analysis based on ITS1, ITS2, or their combination always yielded trees of similar topology. The results support the morphological classifications of bivalve and are nearly consistent with classification of two subfamilies (Chlamydinae and Pectininae) formulated by Waller. However, A. irradians, together with A. opercularis made up of genera Amusium, evidences that they may belong to the subfamily Pectinidae. The data are incompatible with the conclusion of Waller who placed them in Chlamydinae by morphological characteristics. These results provide new insights into the evolutionary relationships among scallop species and contribute to the improvement of existing classification systems.  相似文献   

梭鱼标准代谢、内源氮排泄与体重和温度的关系   总被引：5，自引：0，他引：5  

线薇薇  朱鑫华 《中国海洋大学学报(自然科学版)》2002,32(3):368-374

在 13.5 ,18,2 1.5 ,2 4和 2 7℃ 5个温度条件下测定了梭鱼 (体重范围 1.88～ 14.0 2 g)的标准代谢率和内源氮排泄率。梭鱼标准代谢率随体重的增加而增加 ,二者的关系为幂函数关系 ;随温度的升高而增加 ,二者的关系为指数关系 ;标准代谢率与体重和温度的关系可用如下方程表示 :RS=0 .12 4 6 W0 .9954 e0 .0 84 1T(r2 =0 .92 2 0 )。梭鱼的氨氮、尿素、总氮及能量的排泄率随体重和温度的增加而增加 ,与体重为幂函数关系 ,与温度的关系为多项式形式。梭鱼氨氮和尿素日排泄率的变幅分别为 0 .15～ 0 .88mg N/d和 0 .0 3～ 0 .2 9mg N/d。不同温度下 ,尿素排泄量占总氮比例在 9.9%～2 2 .4 9%之间 ,随温度升高该值有逐渐增大的趋势。  相似文献   

A seismic reconnaissance survey of the northern Congo Fan     

Gabriele Uenzelmann-Neben  Volkhard Spiess  Ulrich Bleil 《Marine Geology》1997,140(3-4):283-306

To study the time-varying influence of the Congo River and the Benguela Current on the deposition at the Angola Continental Margin, a high-resolution reflection seismic survey was carried out on the northern Congo Fan. Four seismostratigraphic units have been defined for the upper 800 m (1000 ms TWT) of the data. The units record different depositional environments, ranging from pre-establishment of the Congo River drainage system to the influence of the Benguela Current. An indication of a general change in the turbidite system is provided by a shift in channel distribution and a relocation of the depocentre of coarse material. The ascent of salt is recorded up to the Pliocene. Gas that has migrated out of Lower Cretaceous shales and that was produced from large quantities of organic matter in the younger sediments can be found on the flanks and on top of the salt domes. In a few places, this gas even ascends to the ocean floor along structural pathways through the topmost unit.  相似文献