19 research outputs found

    Natural Spawning And Rearing Of Mangrove Red Snapper, Lutjanus Agentimaculatus, Larvae In Captivity

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    Mangrove red snapper (Lutjanus argentimaculatus, Forsskål) spawned naturally in captivity, without the use of hormones or other treatments, from May 21 to September 15, 1999. Each female laid an average 2,350,000 eggs. Larvae were reared in 4-ton circular fiberglass tanks. They were first fed S-type rotifers (Brachionus rotundiformis). Later, Artemia nauplii and cope- pods were added to the diet. They were weaned onto an artificial diet. Metamorphosis began at 18 days when the larvae reached 10.5 mm total length and was complete by day 30 when lar- vae were 17.2 mm. From day 26, large larvae (over 25 mm) cannibalized their smaller siblings. Abnormalities were observed in 4.9% of the individuals. At 50 days, the larvae rearing trial pro- duced juveniles of 49 mm average total length with a survival of 10.8-32.3%

    Optimal Dose of Total Residual Oxidants for Hybrid Tilapia (Oreochromis mossambicus x O. niloticus) and Whiteleg Shrimp (Litopenaeus vannamei) in Ozone-Treated Sea Water

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    The purpose of this study was to use total residual oxidants (TRO) as an indicator for determining the optimal ozone dosage needed to control water quality and thereby enhance survival of cultivated aquatic organisms. When the TRO concentration was maintained at 0.16 mg/l for two hours, the total bacteria plate count dropped from 7.7 x 103 CFU/ml in the untreated sea water to less than 10 CFU/ml in the ozone-treated sea water. The TRO con- centration in the ozone-treated water was well below the 96-h LC50 for hybrid tilapia (Oreochromis mossambicus x O. niloticus) and whiteleg shrimp (Litopenaeus vannamei) determined in this study. Hence, adjust- ment of the ozone concentration in aquacultural sea water is a viable option that simultaneously kills the majority of harmful bacteria in the water and enhances survival of cultivated aquatic organisms

    Antifungal Activities of Compounds Produced by Newly Isolated <i>Acrocarpospora</i> Strains

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    In our continued search for bioactive metabolites from cultures of rare Actinobacteria resources from all over Taiwan and various natural ecological environments, an active antimicrobial strain of Acrocarpospora punica 04107M was collected in Taitung County in Taiwan and prepared from soil. The bioassay-guided fractionation of the BuOH extract of a culture broth from A. punica 04107M led to the isolation of five previously undescribed compounds: Acrocarposporins A–E (Compounds 1–5). All the constituents were confirmed by HRESIMS and 1D- and 2D-NMR spectroscopy. Their antifungal activity was also evaluated. Our results showed that four constituents (Compounds 1, 2, 4, and 5) possessed mild antifungal activity against Aspergillus niger, Penicillium italicum, Candida albicans, and Saccharomyces cerevisiae. It is worth mentioning that the chemical composition of Acrocarpospora punica 04107M has never been studied. This is the first report on diterpenoid metabolites from the genus Acrocarpospora

    A probe-based qRT-PCR method to profile immunological gene expression in blood of captive beluga whales (Delphinapterus leucas)

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    Cytokines are fundamental for a functioning immune system, and thus potentially serve as important indicators of animal health. Quantitation of mRNA using quantitative reverse transcription polymerase chain reaction (qRT-PCR) is an established immunological technique. It is particularly suitable for detecting the expression of proteins against which monoclonal antibodies are not available. In this study, we developed a probe-based quantitative gene expression assay for immunological assessment of captive beluga whales (Delphinapterus leucas) that is one of the most common cetacean species on display in aquariums worldwide. Six immunologically relevant genes (IL-2Rα, -4, -10, -12, TNFα, and IFNγ) were selected for analysis, and two validated housekeeping genes (PGK1 and RPL4) with stable expression were used as reference genes. Sixteen blood samples were obtained from four animals with different health conditions and stored in RNAlater™ solution. These samples were used for RNA extraction followed by qRT-PCR analysis. Analysis of gene transcripts was performed by relative quantitation using the comparative Cq method with the integration of amplification efficiency and two reference genes. The expression levels of each gene in the samples from clinically healthy animals were normally distributed. Transcript outliers for IL-2Rα, IL-4, IL-12, TNFα, and IFNγ were noticed in four samples collected from two clinically unhealthy animals. This assay has the potential to identify immune system deviation from normal state, which is caused by health problems. Furthermore, knowing the immune status of captive cetaceans could help both trainers and veterinarians in implementing preventive approaches prior to disease onset

    Selection of reference genes for RT-qPCR studies in blood of beluga whales ( Delphinapterus leucas ) Selection of reference genes for RT-qPCR studies in blood of beluga whales 2 (Delphinapterus leucas)

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    Reverse transcription-quantitative PCR (RT-qPCR) is used for research in gene expression, and it is vital to choose appropriate housekeeping genes (HKGs) as reference genes to obtain correct result. The purpose of this study is to determine stably expressed HKGs in blood of beluga whales (Delphinapterus leucas) that can be the appropriate reference genes in relative quantification in gene expression research. Sixty blood samples were taken from 4 beluga whales. Thirteen candidate HKGs (ACTB, B2M, GAPDH, HPRT1, LDHB, PGK1, RPL4, RPL8, RPL18, RPS9, RPS18, TFRC, YWHAZ) were tested using RT-qPCR. 16 Reverse transcription-quantitative PCR (RT-qPCR) is used for research in gene expression, 17 and it is vital to choose appropriate housekeeping genes (HKGs) as reference genes to obtain 18 correct result. The purpose of this study is to determine stably expressed HKGs in blood of 19 beluga whales (Delphinapterus leucas) that can be the appropriate reference genes in relative 20 quantification in gene expression research. Sixty blood samples were taken from 4 beluga whales

    Selection of reference genes for RT-qPCR studies in blood of beluga whales (Delphinapterus leucas)

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    Reverse transcription quantitative PCR (RT-qPCR) is used for research in gene expression, and it is vital to choose appropriate housekeeping genes (HKGs) as reference genes to obtain correct results. The purpose of this study is to determine stably expressed HKGs in blood of beluga whales (Delphinapterus leucas) that can be the appropriate reference genes in relative quantification in gene expression research. Sixty blood samples were taken from four beluga whales. Thirteen candidate HKGs (ACTB, B2M, GAPDH, HPRT1, LDHB, PGK1, RPL4, RPL8, RPL18, RPS9, RPS18, TFRC, YWHAZ) were tested using RT-qPCR. The stability values of the HKGs were determined by four different algorithms. Comprehensive analysis of the results revealed that RPL4, PGK1 and ACTB are strongly recommended for use in future RT-qPCR studies in beluga blood samples. This research provides recommendation of reference gene selection, which may contribute to further mRNA relative quantification research in the peripheral blood leukocytes in captive cetaceans. The gene expression assessment of the immune components in blood have the potential to serve as an important approach to evaluating cetacean health influenced by environmental insults

    Evaluating the Accuracy of Morphological Identification of Larval Fishes by Applying DNA Barcoding

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    <div><p>Due to insufficient morphological diagnostic characters in larval fishes, it is easy to misidentify them and difficult to key to the genus or species level. The identification results from different laboratories are often inconsistent. This experiment aims to find out, by applying DNA barcoding, how inconsistent the identifications can be among larval fish taxonomists. One hundred morphotypes of larval fishes were chosen as test specimens. The fishes were collected with either larval fish nets or light traps in the northern, southern and northwestern waters of Taiwan. After their body lengths (SL) were measured and specimen photos were taken, all specimens were delivered, in turn, to five laboratories (A–E) in Taiwan to be identified independently. When all the results were collected, these specimens were then identified using COI barcoding. Out of a total of 100 specimens, 87 were identified to the family level, 79 to the genus level and 69 to the species level, based on the COI database currently available. The average accuracy rates of the five laboratories were quite low: 80.1% for the family level, 41.1% for the genus level, and 13.5% for the species level. If the results marked as “unidentified” were excluded from calculations, the rates went up to 75.4% and 43.7% for the genus and species levels, respectively. Thus, we suggest that larval fish identification should be more conservative; i.e., when in doubt, it is better to key only to the family and not to the genus or species level. As to the most misidentified families in our experiment, they were Sparidae, Scorpaenidae, Scombridae, Serranidae and Malacanthidae. On the other hand, <em>Mene maculata</em> and <em>Microcanthus strigatus</em> were all correctly identified to the species level because their larvae have distinct morphology. Nevertheless, barcoding remains one of the best methods to confirm species identification.</p> </div

    The Isolated and Combined Effects of Folic Acid and Synthetic Bioactive Compounds against Aβ(25-35)-Induced Toxicity in Human Microglial Cells

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    Folic acid plays an important role in neuronal development. A series of newly synthesized bioactive compounds (NSCs) was reported to exhibit immunoactive and neuroprotective functions. The isolated and combined effects of folic acid and NSCs against β-amyloid (Aβ)-induced cytotoxicity are poorly understood. These effects were tested using human microglia cells (C13NJ) subjected to Aβ(25-35) challenge. According to an MTT assay, treatment of C13NJ cells with Aβ(25-35) at 10~100 μM for 48 h induced 18%~43% cellular death in a dose-dependent manner (p &lt; 0.05). Aβ(25-35) treatment at 25 μM induced nitrite oxide (NO) release, elevated superoxide production, and reduced the distribution of cells in the S phase. Preincubation of C13NJ with 100 μM folic acid protected against Aβ(25-35)-induced cell death, which coincided with a reduction in NO release by folic acid supplements. NSC47 at a level of 50 μM protected against Aβ(25-35)-induced cell death and reduced Aβ-promoted superoxide production (p &lt; 0.05). Folic acid in combination with NSC47 at their cytoprotective doses did not synergistically ameliorate Aβ(25-35)-associated NO release, superoxide production, or cell cycle arrest. Taken together, folic acid or NSC treatment alone, but not the combined regimen, protected against Aβ(25-35)-induced cell death, which may partially, if not completely, be mediated by free radical-scavenging effects
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