Institutional Repository of South China Sea Institute of Oceanology, CAS
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细菌重组系统及其应用研究进展
No full text利用重组酶和辅助蛋白共同作用于DNA片段上,使不同基因重新组合以完成基因重组的现象在细菌中广泛存在,基因重组对于细菌的遗传多样性、进化等具有重要意义。目前,细菌基因重组主要分为同源重组、位点特异性重组和转座重组3种类型。本文主要对细菌重组系统重组酶的种类、作用机制及其在细菌遗传操作中的应用策略进行阐述
Yeast and Corn Flour Supplement to Enhance Large-scale Culture Efficiency of Marine Copepod Tisbe furcata, a Potential Live Food for Fish Larvae
No full textCopepods can generally provide balanced nutrition for first-feeding of fish larvae, and Tisbe furcata is recognized as a potential larval diet for aquaculture. In this study we examined the effects of feed composition and water quality on the population density of T. furcata over 20 days in large-scale culture. Results showed that the population density of T. furcata increased when fed a diet supplemented with yeast and corn flour (P< 0.05) and reached a greater mass compared to three other diet compositions. During culture, nitrite and phosphate concentrations in the water were positively correlated with the population density of T. furcata. The concentration levels of nitrate and ammonia nitrogen were low, and did not reveal any negative effects on the growth of T. furcata. We found that the feed formula that contained yeast and corn flour in given quantities did affect the quality of water, even in high culture densities. Yeast and corn flour could constitute promising candidates for feed supplements for T. furcata, or other copepod species in the future
Chroman-4-one and pyrano[4,3-b] chromenone derivatives from the mangrove endophytic fungus Diaporthe phaseolorum SKS019
No full textSeven new compounds: diaporchromanones A-D (1-4), (-)-phomopsichin A (5a), (+)-phomopsichin B (6a), and (-)-diaporchromone A (7), along with the known (+)-phomopsichin A (5b) and (-)-phomopsichin B (6b) were isolated from an endophytic fungus Diaporthe phaseolorum SKS019. The structures of the new compounds, including their absolute configurations, were determined on the basis of HRESIMS and NMR spectroscopic data, and experimental ECD and Rh-2(OCOCF3)(4) induced CD spectra analyses. Diaporchromanone A (1)/B (2), and C (3)/D (4) are two pairs of 3-epimers, and their structures possessing 3-substituted-chroman-4-one skeleton are rarely found in natural sources. (-)-Phomopsichin A (5a) and (+)-phomopsichin B (6a) are enantiomers of (+)-phomopsichin A (5b) and (-)-phomopsichin B (6b), respectively. All of the isolates were evaluated for their inhibitory effects against osteoclastogenesis in the RAW 264.7 cell line using luciferase reporter gene assays. Compounds 3-6b exhibited moderate inhibitory effects on osteoclastogenesis by suppressing the receptor activator of NF-kappa B by ligand-induced NF-kappa B activation
Proteome Analysis Reveals Extensive Light Stress-Response Reprogramming in the Seagrass Zostera muelleri (Alismatales, Zosteraceae) Metabolism
No full textSeagrasses are marine ecosystem engineers that are currently declining in abundance at an alarming rate due to both natural and anthropogenic disturbances in ecological niches. Despite reports on the morphological and physiological adaptations of seagrasses to extreme environments, little is known of the molecular mechanisms underlying photo-acclimation, and/or tolerance in these marine plants. This study applies the two-dimensional isoelectric focusing (2D-IEF) proteomics approach to identify photo-acclimation/tolerance proteins in the marine seagrass Zostera muelleri. For this, Z. muelleri was exposed for 10 days in laboratory mesocosms to saturating (control, 200 mu mol photons m(-2) s(-1)), super-saturating (SSL, 600 mu mol photons m(-2) s(-1)), and limited light (LL, 20 mu mol photons m(-2) s(-1)) irradiance conditions. Using LC-MS/MS analysis, 93 and 40 protein spots were differentially regulated under SSL and LL conditions, respectively, when compared to the control. In contrast to the LL condition, Z. muelleri robustly tolerated super-saturation light than control conditions, evidenced by their higher relative maximum electron transport rate and minimum saturating irradiance values. Proteomic analyses revealed up-regulation and/or appearances of proteins belonging to the Calvin-Benson and Krebs cycle, glycolysis, the glycine cleavage system of photorespiration, and the antioxidant system. These proteins, together with those from the inter-connected glutamate-proline-GABA pathway, shaped Z. muelleri photosynthesis and growth under SSL conditions. In contrast, the LL condition negatively impacted the metabolic activities of Z. muelleri by down-regulating key metabolic enzymes for photosynthesis and the metabolism of carbohydrates and amino acids, which is consistent with the observation with lower photosynthetic performance under LL condition. This study provides novel insights into the underlying molecular photo-acclimation mechanisms in Z. muelleri, in addition to identifying protein-based biomarkers that could be used as early indicators to detect acute/chronic light stress in seagrasses to monitor seagrass health
Can private management compensate the ineffective marine reserves in China?
No full textMarine reserves (MRs) have emerged as a preferred method to protect coral reefs from overfishing and human disturbance. However, due to ineffective enforcement by governments, many MRs have been reduced to mere "paper parks" which fail to achieve conservation goals. This is especially true in countries such as China where compliance is low and resources dedicated to enforcement may be scarce. Privately managed marine reserves (PMMRs) may be effective in areas where government enforcement is lacking. To determine if PMMRs are a viable alternative strategy to protect coral reefs, we surveyed and compared fish assemblages and coral coverage in national MRs in Sanya, China to areas of reef privately leased to and managed by dive operators and hospitality industries. We found higher fish abundances and fish sizes in PMMR sites than in MR sites. However, while PMMRs are protected from fishing, other human impacts such as marine debris and illegal coral collection were evident in most tourist sites. Despite protection, long-term monitoring data of PMMRs revealed that in recent years, fish abundances have slightly recovered but species richness has not, indicating the need for a more comprehensive coral reef management plan. We strongly recommend coupling PMMRs with expertise supported regulations as an alternative coral reef management strategy in China
Incomplete sterility of hybrids produced by Crassostrea hongkongensis femalexCrassostrea gigas male crosses
No full textChrodrimanins K-N and Related Meroterpenoids from the Fungus Penicillium sp. SCS-KFD09 Isolated from a Marine Worm, Sipunculus nudus
No full textSix new meroterpenoids, chrodrimanins K-N (1-4), including two uncommon chlorinated one (1 and 2), and verruculides B2 (5) and B3 (6), as well as seven known ones (7-13), were isolated from the fermentation broth of Penitillinm sp. SCS-KFD09, isolated from a marine worm, Sipunculus nuchis, from Haikou Bay, China., The, structures including the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data, X-ray diffraction analysis, and ECD spectra analysis along with quantum ECD calculations. In addition, the X-ray crystal structures and, absolute configurations :of two previously reported tneroterpenoids, chrodrimanins F (9) and A (11), are described for the first time. Compounds 1, 4, and 7 displayed anti-H1N1 activity with IC50 values of-74,, 58, and 34 mu M, respectively, while compound 5 showed, weak inhibitory activity against Staphylococcus atireas with an MIC of 32 mu g/mL
Characteristics of picoplankton abundances during a Thalassiosira diporocyclus bloom in the Taiwan Bank in late winter
No full textTo understand the variations of picoplankton (Prochlorococcus, Synechococcus, picoeukaryotes, and heterotrophic bacteria) abundances during diatom bloom, the distribution of picoplankton in the Taiwan Bank, South China Sea was investigated using flow cytometry during a Thalassiosira diporocyclus bloom in March 2016. The results indicated an abrupt abundance decrease for Prochlorococcus, Synechococcus, and picoeukaryotes within the bloom area while the abundance of heterotrophic bacteria showed no significant difference between the bloom and non-bloom areas. We found two sub-groups of heterotrophic bacteria: high- and low-nucleic acid content (HNA and LNA) bacteria with HNA dominated in the bloom area whereas LNA dominated in the non-bloom area. Among the picoplankton components, HNA represented the highest (61.1%) carbon biomass in the bloom area while picoeukaryotes represented the highest (37.6%) in the non-bloom area. Our findings implied that heterotrophic bacteria, especially HNA, played an essential role during the diatom bloom. (C) 2017 Elsevier Ltd. All rights reserved
Molecular identification and functional characterization of a tumor necrosis factor (TNF) gene in Crassostrea hongkongensis
No full textTumor necrosis factor superfamily (TNFSF) represents a group of multifunctional inflammatory cytokines that have been shown to participate in a variety of pathological and immunological process. However, the functions of these proteins in oyster are still poorly understood. In the present study, an oyster TNF homolog (named ChTNF) was identified from a cDNA library of Crassostrea hongkongensis. The complete cDNA of ChTNF was 2457 by in length containing an open reading frame (ORF) of 1044 bp, a 5'-untranslated region (UTR) of 381 bp and a 3'-UTR of 1032 bp. The deduced ChTNF protein consisted of 347 amino acids with a characteristic transmembrane domain and a typical TNF homology domain (THD). Quantitative real-time PCR analysis revealed that ChTNF was broadly expressed in various oyster tissues and different stages of embryonic development. In addition, transcriptional analysis indicated that ChTNF transcription levels in hemocytes were increased significantly in pathogen challenge groups (Vibrio alginolyticus and Staphylococcus haemolyticus) compared to that in the control. Moreover, in vitro PAMP (lipopolysaccharide and peptidoglycan) treatments showed a stimulatory effect on the expression of ChTNF in the primary cultured hemocytes of C. hongkongensis. Finally, dual-luciferase reporter assays revealed that ChTNF could activate the NF-kappa B-Luc reporter in a dose-dependent manner in HEK293T cells. Altogether, these findings may provide valuable information regarding oyster TNFs and its role in innate immunity. (C) 2017 Elsevier GmbH. All rights reserved
Toxicity study of oxalicumone A, derived from a marine-derived fungus Penicillium oxalicum, in cultured renal epithelial cells
No full textOxalicumone A (POA), a novel dihydrothiophene-condensed chromone, was isolated from the marine-derived fungus Penicillium oxalicum. Previous reports demonstrated that POA exhibits strong activity against human carcinoma cells, thus it has been suggested as a bioactive anticancer agent. To research the toxic effect of POA on cultured normal epithelial human kidney-2 (HK-2) cells and evaluate its clinical safety, cell survival was evaluated by the Cell Counting Kit-8 assay and apoptosis was evaluated by Hoechst 33258 staining, flow cytometry, caspase-3 activity assay and western blotting. 2',7'-Dichlorofluorescin diacetate and JC-1 dye staining was used to evaluate reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP), respectively. The results indicated that POA inhibited HK-2 cell growth and promoted apoptosis, by increasing levels of Fas cell surface cell receptor and the B-cell lymphoma 2 associated protein X apoptosis regulator (Bax)/B-cell lymphoma 2 apoptosis regulator (Bcl-2) ratio. POA treatment also induced release of ROS and loss of MMP in HK-2 cells. Compared with untreated control, a significant decrease was also demonstrated in superoxide dismutase activity and glutathione content with POA treatment, accompanied by enhanced release of N-acetyl-beta-D-glucosaminidase, increased leakage of lactate dehydrogenase, increased malondialdehyde formation and increased release of nitric oxide. In conclusion, the present in vitro study revealed that POA exhibits antiproliferation activity on HK-2 cells, through stimulation of apoptosis and oxidative stress injury, which may be relevant to its clinical application. The present study may, therefore, offer valuable new information regarding the use of POA as a candidate novel antitumor drug for clinical use