Bacterial diversity in Arctic marine sediment determined by culture-dependent and-independent approaches     

LIN Xuezheng  WANG Zhen  CHE Shuai  SONG Weizhi  YI Dan 《极地研究(英文版)》2014,(1):46-53

Bacterial diversity in surface sediment from the Arctic Ocean was investigated by culture-dependent and-independent approaches. Conventional culture-dependent techniques revealed 11 strains based on their distinct morphological characteristics on marine Zobell 2216E agar plates. Phylogenetic analysis showed that these isolates belonged to three major lineages of the Bacteria, γ-proteobacteria, Bacteroidetes and Actinobacteria, and that they included 10 genera. Most isolates were psychrotrophic, and NaCl was not necessary for their growth. Furthermore, they exhibited activity of at least one extracellular hydrolytic enzyme at 4°C and had various abilities to assimilate carbon sources. A total of 67 phylotypes were detected among 142 clones based on the 16S rRNA library of the total community DNA and grouped into nine major lineages of bacteria. Phylotypes affiliated with γ-, δ- and ε-proteobacteria accounted for 36.7%, 21.8% and 16.9% of the total clones, respectively. The rest of the clones belonged to Bacteroidetes, α-proteobacteria, Actinobacteria, Fusobacteria, Nitrospirae and an unclassified group.  相似文献   

Archaeal diversity and abundance within different layers of summer sea-ice and seawater from Prydz Bay,Antarctica     

MA Jifei  DU Zongjun  LUO Wei  YU Yong  ZENG Yixin  CHEN Bo  LI Huirong 《极地研究(英文版)》2014,(1):54-60

Fluorescence in-situ hybridization （FISH） and 16S rRNA gene clone library analyses were used to determine the abundance and diversity of archaea in Prydz Bay, Antarctica. Correlation analysis was also performed to assess links between physicochemical parameters and archaeal abundance and diversity within the sea-ice. Samples of sea-ice and seawater were collected during the 26th Chinese National Antarctic Research Expedition. The results of FISH showed that archaea were relatively abundant within the top layer of the sea-ice, and correlation analysis suggested that the concentration of 4NH＋ might be one of the main factors underlying this distribution pattern. However, using 16S rRNA gene libraries, archaea were not detected in the top and middle layers of the sea-ice. All archaeal clones obtained from the bottom layer of the sea-ice were grouped into the Marine Group I Crenarchaeota while the archaeal clones from seawater were assigned to Marine Group I Crenarchaeota, Marine Group II Euryarchaeota, and Marine Group III Euryarchaeota. Overall, the ifndings of this study showed that the diversity of archaea in the sea-ice in Prydz Bay was low.  相似文献   

马氏珠母贝外套膜中央膜与边缘膜荧光定量PCR分析中内参基因的筛选     

闫芳  罗少杰  田群莉  焦钰  邓岳文 《广东海洋大学学报》2014,(6):6-11

为筛选能在马氏珠母贝外套膜边缘膜与中央膜区域稳定表达的内参基因,应用荧光定量PCR 技术,对3-磷酸脱氢酶（GAPDH）、β-肌动蛋白（β-actin）、胆色素原脱氨酶（PBGD）、微管蛋白（TUB）、TATA 盒结合蛋白（TBP）、磷脂酶A2（PLA-2）、葡萄糖苷酶（GUSB）、18S 核糖体rRNA（18SrRNA）等8 个常用的内参基因在马氏珠母贝外套膜边缘膜与中央膜区域的表达情况进行分析,并利用geNorm、NormFinder、BestKeeper 及RefFinder 软件对8 个内参基因的表达稳定性进行分析.结果表明：8 个内参基因均可获得特异性扩增产物,但稳定性各异, 其在外套膜边缘膜和中央膜区的表达稳定性顺序依次为PBGD/TBP〉TUB〉GUSB〉18SrRNA〉PLA-2〉GAPDH〉 β-actin;在荧光定量PCR 中,PBGD 和TBP 在马氏珠母贝外套膜边缘膜和中央膜区的表达比较稳定,为研究贝壳矿化机制中理想的内参基因.  相似文献   

A rapid assessment of Scleractinian and non-Scleractinian coral growth forms along the Saudi Arabian coast,Red Sea     

Abdulmohsin A. Al-Sofyani  N. Marimuthu  and J. Jerald Wilson 《中国海洋大学学报(英文版)》2014,13(2):243-248

In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands(44.55%±11.10% cover) followed by tabular forms in the Doga Islands(ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area(58.89%±15.11% cover) followed by the Jeddah coast(24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah(10.70%±8.21%) and Al-Wajh(9.81%±6.69%). The live coral cover(including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acroporid corals was greater in the southern region than in the northern and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah(Northern region) and the second one comprised the middle and southern regions(Jeddah to Farassan Islands), and one outlier Rabigh.  相似文献   

Construction of a full-length cDNA library of Solen grandis Dunker and identification of defense- and immune-related genes     

SUN Guohua  LIU Xiangquan  REN Lihua  YANG Jianmin  WEI Xiumei  and YANG Jialong 《中国海洋大学学报(英文版)》2014,13(1):169-173

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Relationship between physical and chemical soil attributes and plant species diversity in tropical mountain ecosystems from Brazil   总被引：2，自引：0，他引：2  

Fernanda de Carvalho  Edward Luis Godoy  Francy J. G. Lisboa  Fatima Maria de Souza Moreira  Francisco Adriano de Souza  Ricardo Luis Louro Berbara  G. Wilson Fernandes 《山地科学学报》2014,11(4):875-883

Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado （savanna）. Different habitats occur according to soil characteristics （e.g., presence of rocks, sand, fertility, hydrology, etc.）. These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us： rocky outcrops, peat bogs, sandy bogs, quartz gravelfields, and ＂cerrado＂ （savanna）. A floristic survey indicated that four families are found at greater frequency： Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus （Poaceae） was the most dominant species in the rocky outcrops, Axonopus siccus （Poaceae） in the peat bogs, Lagenocarpus rigidus （Cyperaceae） in the sandy bogs, Schizachyrium tenerum （Poaceae） in the cerrado, while Vellozia sp. 8 （Velloziaceae） dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.  相似文献   

Cyclones influence native plant diversity on 22 remote high islands of French Polynesia and Pitcairn (eastern Polynesia)     

Sébastien Larrue 《自然地理学》2014,35(6):497-513

I examined the relative influence of eight spatial characteristics on native plant diversity in 22 volcanic high islands of eastern Polynesia. The characteristics used as potential predictors in this study included island area, highest elevation, distance to the nearest continent, distance to the nearest archipelago, distance to the nearest similar island, index of isolation, distance to the largest and highest island of Tahiti, and distance to the “cyclonic alley.” Among characteristics studied, native plant diversity (indigenous and endemic species) was primarily linked with the island area and highest elevation of the islands. Contemporary cyclones were an important predictor of indigenous plant diversity in the remote islands surveyed. In the study area, this result suggests that cyclones, moving from the west Pacific Ocean basin to the eastern Polynesian islands, have provided more indigenous species to the remote high islands located close to the cyclonic alley. Isolation did not appear as a significant predictor of native plant diversity in the high islands surveyed, possibly due to a stepping-stone-island effect and the proximity of the cyclonic alley. These findings suggest that isolation could be tempered by a cyclonic-transport-flow effect in the study area, thus reducing the effective distance of the remote islands from the mainland source pool for seed dispersal.  相似文献   

中华乌塘鳢(Bostrychus sinensis) GPx7和GPx8基因的克隆、表达与酶活性分析     

丁浪  夏立萍  沈斌  张建设 《海洋与湖沼》2022,53(3):697-709

中华乌塘鳢(Bostrychus sinensis)属于广盐广温、低氧耐受性强、药用价值高的鱼类,为我国东南沿海重要养殖对象。谷胱甘肽过氧化物酶(glutathione peroxidase,GPx)是生物体内重要的抗氧化酶,能够清除过氧化氢防止机体生物膜氧化受损,研究中华乌塘鳢GPx基因对其养殖及海洋生态研究具有重要意义。利用分子克隆技术获得了中华乌塘鳢GPx7和GPx8(分别命名为BsGPx7和BsGPx8)的cDNA序列。BsGPx7编码186个氨基酸,含有2个半胱氨酸(Cys⁵⁶和Cys⁸⁵)催化位点;BsGPx8编码210个氨基酸,含有1个半胱氨酸(Cys¹⁰⁹)催化位点。利用RT-PCR方法研究了BsGPx7、BsGPx8基因在中华乌塘鳢组织中的分布表达,以及不同浓度镉离子(7.5,15,30 mg/L)胁迫下BsGPx7、BsGPx8基因的表达量变化。结果显示,BsGPx7和BsGPx8在组织中呈泛在性表达,其中肝脏的表达量最高,其次是鳃和皮肤。不同浓度的镉离子胁迫下,BsGPx7基因在鳃和皮肤中的表达量均显著上调(P<0.05),BsGPx8基因在肝脏、鳃和皮肤中的表达量均显著上调(P<0.05)。成功构建了原核表达载体,表达并纯化获得了BsGPx7重组蛋白(rBsGPx7)。对rBsGPx7在不同温度和pH条件下的酶活性进行了测定,表明rBsGPx7在35℃和pH 8条件下酶活性最高。综上提示,BsGPx7与BsGPx8参与了机体对抗镉离子诱导的氧化应激的过程,可能在抗氧化防御中起一定作用。  相似文献   

Comparative mitochondrial genome analysis of Sesarmidae and its phylogenetic implications     

Ying Zhang  Lei Meng  Liming Wei  Bingjian Liu  Liqin Liu  Zhenming Lü  Yang Gao  Li Gong 《海洋学报(英文版)》2022,41(8):62-73

Here, we sequenced the complete mitogenome of Parasesarma eumolpe (Brachyura: Grapsoidea: Sesarmidae) for the first time. The characteristics of this newly sequenced mitogenome were described and compared with other Sesarmidae species. The 15 646-bp mitogenome contains 13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and an A-T rich region. All of the PCGs are initiated by the start codon ATN and terminated by the standard TAN codon or an incomplete T. The pairwise Ka/Ks ratio analysis shows that all 13 PCGs are under purifying selection, whereas the ATP8 gene is an outlier, with pairwise comparison values ranging from neutral selection (0.000) to positive selection (1.039). The gene arrangement of P. eumolpe compared with ancestral Decapoda shows the translocation of two tRNAs (tRNA-His and tRNA-Gln), which is identical to other Sesarmidae species. Phylogenetic analyses show that all Sesarmidae species are placed into one group, and the polyphyly of Eriphioidea, Ocypodoidea, and Grapsoidea is well supported. The relationship between gaps in the QIM region and the phylogeny of Sesarmidae is analyzed. It is obvious that both the G5 (the gap between Q and I) and G6 (the gap between I and M) decrease progressively with the evolution process. These results will help to better understand the genomic evolution within Sesarmidae and provide insights into the phylogeny of Brachyura.  相似文献   

Spatial and diel variations of the prokaryotic community in the Phaeocystis globosa blooms area of Beibu Gulf,China     

Cheng He  Sha Xu  Shuqun Song  Caiwen Li 《海洋学报(英文版)》2022,41(12):87-97

While prokaryotes play key roles in nutrient cycling and energy flow during Phaeocystis globosa blooms, the information on the spatial and diel temporal distribution of the prokaryotic community during Phaeocystis blooms remains scarce. In January 2019, we used high-throughput sequencing of the 16S rRNA gene to explore the spatial and diel variations of particle-attached (PA) and free-living (FL) prokaryotic communities during the blooming phase of P. globosa in Beibu Gulf, Guangxi, China. The results suggested a significant spatial variation pattern in the horizontal distribution of prokaryotic communities, while there was no significant difference in the vertical direction. Both spatial distance and environmental variables shaped the horizontal distribution of the prokaryotic community structure, while environmental variables, particularly the abundance of P. globosa colony and Chl a, showed more significant influence and were closely related to the structure and variation of the prokaryotic community. Strong vertical mixing of the water column disrupted the vertical structure heterogeneity of the prokaryotic community in winter. There were significant differences in the diel samples of PA prokaryotic communities, but not in the FL prokaryotic communities. Nitrate, ammonium and the abundance of P. globosa colony were the key environmental variables impacting the diel variations of prokaryotic communities over the sampling period. The present study provided valuable information to depict the spatial-temporal variations of the microbial community and its association with environmental parameters during P. globosa bloom in the tropical gulf.  相似文献