Karenia is one of the most harmful and representative red tide genus in a temperate zone. Blooms caused by this genus have resulted in massive fish death in the South China Sea and the East China Sea. However, the pot...Karenia is one of the most harmful and representative red tide genus in a temperate zone. Blooms caused by this genus have resulted in massive fish death in the South China Sea and the East China Sea. However, the potential effects of this dinoflagellate on human health through the transfer of toxins via marine food webs, and the mechanisms of toxicity, are still unknown. Therefore, we examined the toxic effects of a strain of K. mikimotoi （isolated from the South China Sea） on the proliferation and morphology of four mammalian cell lines （two normal cell lines and two cancer cell lines）. In addition, we carried out a preliminary investigation on the mechanism of toxicity of the alga. The results show that the polar lipid-soluble component ofK. mikimotoi significantly inhibited proliferation of the four cell lines, and resulted in the ceils becoming spherical, swollen and damaged. The result of Annexin V and PI double-staining confirmed that cell membranes were disrupted. The malonaldehyde （MDA） contents in the medium of the four cell lines treated with the polar-lipid extracts all increased significantly, which indicates that the polar-lipid toxins produced by K. rnikimotoi could adversely affect mammalian cells by inducing lipid peroxidation. We conclude that K. mikimotoi is a potential threat to human health, and the comprehensive effect of this dinoflagellate and its mechanisms should be investigated further.展开更多
Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumb...Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene(COI) was used to identifing five sea cucumber species(Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31 I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible.展开更多
Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rare...Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.展开更多
The effect of dietary phosphorus on the growth and body components of juvenile Syechogobius hasta was determined. Different percentages of dietary phosphorus （0.63, 0.77, 0.93, 1.06, 1.22 and 1.36） were tested by fe...The effect of dietary phosphorus on the growth and body components of juvenile Syechogobius hasta was determined. Different percentages of dietary phosphorus （0.63, 0.77, 0.93, 1.06, 1.22 and 1.36） were tested by feeding the fish （body weight, 15.81 ±：0.32 g; 20 individuals each group; 3 groups each percentage） at a surplus of 5%-10% above satiation for 35d. Dietary phosphorus did not significantly affect the specific growth rate, teed intake, feed conversion ratio and protein efficiency rate. Nitrogen retention was lbund to be the highest in fish fed the diet contatimg 1.06% of phosphorus; however, this was not significantly different from other diets. Fish ted the diet containing 0.93% of phosphorus showed the highest phosphorus retention; similar phosphorus retention rates were found in fish fed the diets containing 0.77% and 1.06% of phosphorus. Fish fed the diet containing the highest percentage of dietary phosphorus were found to contain the least whole body lipid, lower than fish fed other diets （P〈0.05）. The protein content increased from 18.59% to 19.55% （although not significant） with the decrease of body lipid content （P〉0.05）. The contents of the whole body ash, whole body phosphorus and vertebrae phosphorus increased with dietary phosphorus percentage up to 1.06 （P〈0.05）, reaching a plateau after that. Dietary phosphorus did not significantly influence the muscle components （protein, lipid and moisture）. Condition factor and hepatosomatic index were the highest in fish fed the diet containing 0.63% of dietary phosphorus; however, this was not significantly different from those of other diets. The second-order polynomial regression of phosphorus retention against dietary phosphorus identified a breakpoint at 0.88% of dietary phosphorus. However, the dietary requirement of phosphorus for maintaining maximum phosphorus storage determined by broken-line analysis of the contents of whole body phosphorus, and ash and vertebrae phosphorus was 1.06% of the diet.展开更多
基金Supported by the National Basic Research Program of China (973 Program) (No. 2010CB428700)the National Natural Science Foundation of China (Nos. U0733006, 40821004)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX2-YW-Q07-02)
文摘Karenia is one of the most harmful and representative red tide genus in a temperate zone. Blooms caused by this genus have resulted in massive fish death in the South China Sea and the East China Sea. However, the potential effects of this dinoflagellate on human health through the transfer of toxins via marine food webs, and the mechanisms of toxicity, are still unknown. Therefore, we examined the toxic effects of a strain of K. mikimotoi （isolated from the South China Sea） on the proliferation and morphology of four mammalian cell lines （two normal cell lines and two cancer cell lines）. In addition, we carried out a preliminary investigation on the mechanism of toxicity of the alga. The results show that the polar lipid-soluble component ofK. mikimotoi significantly inhibited proliferation of the four cell lines, and resulted in the ceils becoming spherical, swollen and damaged. The result of Annexin V and PI double-staining confirmed that cell membranes were disrupted. The malonaldehyde （MDA） contents in the medium of the four cell lines treated with the polar-lipid extracts all increased significantly, which indicates that the polar-lipid toxins produced by K. rnikimotoi could adversely affect mammalian cells by inducing lipid peroxidation. We conclude that K. mikimotoi is a potential threat to human health, and the comprehensive effect of this dinoflagellate and its mechanisms should be investigated further.
基金supported by National Natural Science Foundation of China (Nos. 31101281 and 31071525)National Marine Public Welfare Scientific Research Project of China (No. 201105029)
文摘Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene(COI) was used to identifing five sea cucumber species(Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31 I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible.
基金Supported by the Qingdao Postdoctoral Application Research Project(No.Y6KY01110N)the National Natural Science Foundation of China(Nos.31472312,41306152,31402283)+2 种基金the Qingdao Innovation Talents Program(No.13-CX-16)the National Key Technologies R&D Program of China(No.2014BAD08B09)the Earmarked Fund for Modem AgroIndustry Technology Research System(No.CARS-48)
文摘Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.
文摘The effect of dietary phosphorus on the growth and body components of juvenile Syechogobius hasta was determined. Different percentages of dietary phosphorus （0.63, 0.77, 0.93, 1.06, 1.22 and 1.36） were tested by feeding the fish （body weight, 15.81 ±：0.32 g; 20 individuals each group; 3 groups each percentage） at a surplus of 5%-10% above satiation for 35d. Dietary phosphorus did not significantly affect the specific growth rate, teed intake, feed conversion ratio and protein efficiency rate. Nitrogen retention was lbund to be the highest in fish fed the diet contatimg 1.06% of phosphorus; however, this was not significantly different from other diets. Fish ted the diet containing 0.93% of phosphorus showed the highest phosphorus retention; similar phosphorus retention rates were found in fish fed the diets containing 0.77% and 1.06% of phosphorus. Fish fed the diet containing the highest percentage of dietary phosphorus were found to contain the least whole body lipid, lower than fish fed other diets （P〈0.05）. The protein content increased from 18.59% to 19.55% （although not significant） with the decrease of body lipid content （P〉0.05）. The contents of the whole body ash, whole body phosphorus and vertebrae phosphorus increased with dietary phosphorus percentage up to 1.06 （P〈0.05）, reaching a plateau after that. Dietary phosphorus did not significantly influence the muscle components （protein, lipid and moisture）. Condition factor and hepatosomatic index were the highest in fish fed the diet containing 0.63% of dietary phosphorus; however, this was not significantly different from those of other diets. The second-order polynomial regression of phosphorus retention against dietary phosphorus identified a breakpoint at 0.88% of dietary phosphorus. However, the dietary requirement of phosphorus for maintaining maximum phosphorus storage determined by broken-line analysis of the contents of whole body phosphorus, and ash and vertebrae phosphorus was 1.06% of the diet.
