Application of rRNA probes and fluorescence in situ hybridization for rapid detection of the toxic dinoflagellate Alexandrium minutum     

唐祥海  于仁成  周名江  于志刚 《中国海洋湖沼学报》2012,30(2):256-263

The dinoflagellate Alexandrium minutum is often associated with harmful algal blooms (HABs). This species consists of many strains that differ in their ability to produce toxins but have similar morphology, making identification difficult. In this study, species-specific rRNA probes were designed for whole-cell fluorescence in situ hybridization (FISH) to distinguish A. minutum from two phylogenetic clades. We acquired the complete SSU to LSU rDNA sequences (GenBank accession numbers JF906989-JF906999) of 11 Alexandrium strains and used these to design rRNA targeted oligonucleotide probes. Three ribotype-specific probes, M-GC-1, M-PC-2, and M-PC-3, were designed. The former is specific for the GC clade ("Global clade") of A. minutum, the majority of which have been found non-toxic, and the latter two are specific for the PSP (paralytic shellfish poisoning)-producing PC clade ("Pacific clade"). The specificity of these three probes was confirmed by FISH. All cells in observed fields of view were fluorescently labeled when probes and target species were incubated under optimized FISH conditions. However, the accessibility of rRNA molecules in ribosomes varied among the probe binding positions. Thus, there was variation in the distribution of positive signals in labeled cells within nucleolus and cytosol (M-GC-1, M-PC-3), or just nucleolus (M-PC-2). Our results provide a methodological basis for studying the biogeography and population dynamics of A. minutum, and providing an early warning of toxic HABs.  相似文献   

Molecular identification and culture observation on <Emphasis Type="Italic">Acrochaete leptochaete</Emphasis> (Chaetophoraceae,Chlorophyta) from China     

邓蕴彦  汤晓荣  黄冰心  滕林宏  丁兰平 《中国海洋湖沼学报》2012,30(3):476-484

Acrochaete leptochaete (Huber) Nielsen (Chaetophoraceae, Chlorophyta) was isolated from the macroalgae Chaetomorpha collected from intertidal pools in Rongcheng, Shandong, China. 18S rDNA combined with ITS regions were used to ascertain the morphological identification of the isolated material. Based on the unialgal culture, asexual reproduction and growth characteristics of A. leptochaete were investigated over wide ranges of temperature and irradiance. Results revealed that asexual reproduction of A. leptochaete could be realized by biflagellate zoospores. The zoospores germinated directly to give self- replicating generations. Zoospore germination was bipolar. A temperature range from 13-21°C and a lower irradiance of 36 μmol/(m2·s) were most favorable for the growth of A. leptochaete. Thallus organization, an important taxonomic criterion for the genus Acrochaete, was affected markedly by temperature and irradiance. Our results extend the knowledge about the species’ general biology and its morphological plasticity. For classification and identification of a simple microphytic algae like A. leptochaete, which are traditionally placed in the class Chaetophoraceae, we propose that molecular tools associated with culture observations are applied.  相似文献   

BAC end sequencing of Pacific white shrimp <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>: a glimpse into the genome of Penaeid shrimp     

赵翠  张晓军  柳承璋  郇聘  李富花  相建海  黄超 《中国海洋湖沼学报》2012,30(3):456-470

Little is known about the genome of Pacific white shrimp (Litopenaeus vannamei). To address this, we conducted BAC (bacterial artificial chromosome) end sequencing of L. vannamei. We selected and sequenced 7 812 BAC clones from the BAC library LvHE from the two ends of the inserts by Sanger sequencing. After trimming and quality filtering, 11 279 BAC end sequences (BESs) including 4 609 paired- ends BESs were obtained. The total length of the BESs was 4 340 753 bp, representing 0.18% of the L. vannamei haploid genome. The lengths of the BESs ranged from 100 bp to 660 bp with an average length of 385 bp. Analysis of the BESs indicated that the L. vannamei genome is AT-rich and that the primary repeats patterns were simple sequence repeats (SSRs) and low complexity sequences. Dinucleotide and hexanucleotide repeats were the most common SSR types in the BESs. The most abundant transposable element was gypsy, which may contribute to the generation of the large genome size of L. vannamei. We successfully annotated 4 519 BESs by BLAST searching, including genes involved in immunity and sex determination. Our results provide an important resource for functional gene studies, map construction and integration, and complete genome assembly for this species.  相似文献   

Effects of temperature fluctuations on cuttlebone formation of cuttlefish Sepia esculenta     

雷舒涵  张秀梅  刘松林  陈四清 《中国海洋湖沼学报》2012,30(4):547-553

The morphological characteristics and the cuttlebone formation of Sepia esculenta exposed to different water temperature fluctuations were investigated under laboratory conditions. Temperature fluctuation cycles (15 cycles, 60 d in total) consisted of the following three regimes of 4 d duration: keeping water temperature in 26°C for 3 d (Group A), 2 d (Group B), 0 d (Group C, control); then keeping water temperature in 16°C for the next 1, 2, 4 d. No significant difference in the survival rate was observed between the control and temperature fluctuation groups (P>0.05). Lamellar depositions in a temperature fluctuation cycle were 2.45±0.02 for Group A, 2.00±0.02 for Group B, and 1.78±0.02 for Group C (P<0.05). The relationship between age and number of lamellas in the cuttlebone of S. esculenta under each water temperature fluctuation could be described as the linear model and the number of lamellas in the cuttlebone did not correspond to actual age. Group A had the highest cuttlebone growth index (CGI), the lowest locular index (LI), and inter-streak distances comparing with those of control group. However, the number of lamellas and LI or CGI showed a quadratic relationship for each temperature fluctuation group. In addition, temperature fluctuations caused the breakage of cuttlebone dark rings, which was considered a thermal mark. The position of the breakage in the dark rings was random. This thermal mark can be used as supplementary information for marking and releasing techniques.  相似文献   

Community structure changes of macrobenthos in the South Yellow Sea   总被引：3，自引：0，他引：3  

�ž���  ���ɽ  ������ 《中国海洋湖沼学报》2012,30(2):248-255

The ecological environment in the Yellow Sea has changed greatly from the 1950s to 1990s and this has had significant impact on marine organisms. In this study, data on soft-sediment macrobenthos occurring in depths from 25 m to 81 m in the South Yellow Sea were used to compare changes in community structure. The agglomerative classification (CLUSTER) and multidimensional scaling (MDS) methods were applied. Five communities were recognized by cluster analysis: 1. The Yellow Sea Cold Water Mass community dominated by cold water species, which changed slightly in species composition since the 1950s; 2. The mixed community with the coexistence of cold water species and warm water species, as had been reported previously; 3. The polychaete-dominated eurythermal community in which the composition changed considerably as some dominant species disappeared or decreased; 4. The Changjiang (Yangtze) River Estuarine community, with some typical estuarine species; 5. The community affected by the Yellow Sea Warm Current. The greatest change occurred in the coastal area, which indicated that the change may be caused by human activities. Macrobenthos in the central region remained almost unchanged, particularly the cold water species shielded by the Yellow Sea Cold Water Mass. The depth, temperature and median grain size of sediments were important factors affecting the distributions of macrobenthos in the South Yellow Sea.  相似文献   

Bromophenols from marine algae with potential anti-diabetic activities     

LIN Xiukun  LIU Ming 《中国海洋大学学报(英文版)》2012,11(4):533-538

Marine algae contain various bromophenols with a variety of biological activities,including antimicrobial,anticancer,and anti-diabetic effects.Here,we briefly review the recent progress in researches on the biomaterials from marine algae,emphasizing the relationship between the structure and the potential anti-diabetic applications.Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B,α-glucosidase,as well as other mechanisms.  相似文献   

Strain and culture medium optimization for production enhancement of prodiginines from marine-derived Streptomyces sp. GQQ-10     

Xueping Li  Guojian Zhang  Tianjiao Zhu  Dehai Li  Qianqun Gu 《中国海洋大学学报(英文版)》2012,11(3):361-365

A mutant (GQQ-M6) of a Sponge-Derived streptomyces sp. GQQ-10 obtained by UV-induced mutation was used for producing prodiginines (PGs). Single factor experiments and orthogonal array design (OAD) methods were employed for medium optimization. In the single factor method, the effects of soluble starch, glucose, soybean flour, yeast extract and sodium acetate on PGs production were investigated individually. In the subsequent OAD experiments, the concentrations of these 5 key nutritional components combined with salinity were further adjusted. The mutant strain GQQ-M6 gave a 2.2-fold higher PGs production than that of the parent strain; OAD experiments offered a PGs yield of 61mg L-1, which was 10 times higher than that of the initial GQQ-10 strain under the original cultivation mode.  相似文献   

Chitosan extends the shelf-life of filleted tilapia (Oreochromis niloticus) during refrigerated storage   总被引：1，自引：0，他引：1  

Rong Cao  Qi Liu  Bangzhong Yin  Biao Wu 《中国海洋大学学报(英文版)》2012,11(3):408-412

Shelf-life extension of aquatic products is of significant economical importance. To determine the potential effect of chitosan on the shelf-life of filleted tilapia, this study analyzed the bacterial community diversity in fresh and spoiled tilapia fillets stored at (4 ± 1)℃ and examined the antimicrobial activity of chitosan against relevant bacteria isolates. Results showed that Pseudomonas (20%) and Aeromonas (16%) were abundant in fresh tilapia fillets, whereas Pseudomonas (52%), Aeromonas (32%) and Staphylococcus (12%) were dominant in the spoiled samples. Chitosan showed wide-spectrum antibacterial activity against bacteria isolated from tilapia and 5.0 g L-1 chitosan was selected for application in preservation. We further determined the shelf-life of chitosan-treated, filleted tilapia stored at (4 ± 1)℃ based on microbiological, biochemical and sensory analyses. Results showed that the shelf-life of chitosan-treated, filleted tilapia was extended to 12 d, whereas that of untreated, control samples was 6 d. These indicate that chitosan, as a natural preservative, has great application potential in the shelf-life extension of tilapia fillets.  相似文献   

民采空区危险性两级模糊综合评判——以招远市北截村为例          下载免费PDF全文

许薇  董杰  尹明泉  管勇 《山东国土资源》2012,28(3):35-38

在充分搜集资料的基础上,对招远市北截村民采空区进行实地勘查,从地质条件、灾害发育程度及采空区特征3个影响因素入手,选取了9个评判因子进行两级模糊综合评判,采取最大隶属度原则确定采空区危险性等级,并进行了评估分区。评判结果能较准确地反应实际情况,为该区地质灾害防治工作及开发建设规划提供了依据。  相似文献   

珠江口盆地流花碳酸盐台地灰岩坑的地震反射特征及成因探讨     

陈端新  吴时国  施和生  赵淑娟 《吉林大学学报(地球科学版)》2012,42(6):1935-1943

早中新世东沙隆起带上发育了大规模的流花碳酸盐台地,上覆巨厚未固结-弱固结泥岩。基于三维地震数据,利用相干体及可视化等方法,在台地上发现了由溶蚀垮塌作用形成的数量众多的椭圆形的灰岩坑。灰岩坑直径一般为200~700 m,最大超过900 m,深度10~90 m;灰岩坑在地震反射上表现为碳酸盐岩顶部垮塌,并导致上覆泥岩地层塌陷;灰岩坑一般沿NWW向断层分布,这些NWW向断层切割中新世碳酸盐岩和上覆海相泥岩地层,绝大多数终止于T₁₀的不整合面。综合分析东沙海区构造和沉积过程认为：发生在晚中新世末期的东沙运动形成了NWW向张扭性断层,为酸性流体提供了运移通道和物质交换场所;东沙运动伴生的基底岩浆活动可能产生了酸性热液流体;东沙运动末期发生强烈的构造抬升和大规模海底暴露,造成地表水沿断层注入,加快了碳酸盐岩的溶蚀速率。在台地底部珠海组砂岩层的高压流体、地表水和岩浆活动可能产生的酸性热液流体的共同溶蚀作用下,碳酸盐岩地层内部产生溶洞,并且越来越大,最终顶部无法承载上覆巨厚泥岩而发生垮塌,形成灰岩坑。流花碳酸盐台地灰岩坑的形成不是简单的暴露溶蚀,而是构造活动影响下深埋藏溶蚀作用的产物。  相似文献