VIGS(Virus-induced gene silencing),a method for posttranscriptional gene silencing,is an effective technique for investigating the activities of genes in plants.Since there is no report for available VIGS system in St...VIGS(Virus-induced gene silencing),a method for posttranscriptional gene silencing,is an effective technique for investigating the activities of genes in plants.Since there is no report for available VIGS system in Styrax japonicus,the application of a VIGS approach that results in a gene knockdown to study gene function is limited.In this study,we compared the characteristics that could affect the viability of VIGS in S.japonicus,including the acetosyringone(AS)concentration,the Agrobacterium’s optical density and the inoculation method.The stable reference genes of S.japonicus were selected to validate the gene’s knockdown by quantitative PCR.As a result,we successfully constructed 2 VIGS systems based on TRV virus:vacuum with AS concentration of 200μmol·L^(-1)and OD600of 0.5,and friction-osmosis with AS concentration of 200μmol·L^(-1)and OD600of 1.0,which silencing efficiency was 83.33%and 74.19%,respectively.The successfully applied VIGS method provides a rapid and effective reverse gene functional analysis approach in S.japonicus to identify unknown gene functions.展开更多
The sea cucumber Stichopus japonicus is one of the"Eight Treasures of Seafood"and contains a number of bioactive components involved in multiple physiological and pharmacological functions.Proteins and pepti...The sea cucumber Stichopus japonicus is one of the"Eight Treasures of Seafood"and contains a number of bioactive components involved in multiple physiological and pharmacological functions.Proteins and peptides are generally considered to be responsible for these beneficial properties.In this study,a total of 3478 proteins and 17390 peptides were identified in Stichopus japonicus by proteomics methods.Among them,4 proteins were involved in 8 metabolic pathways,especially oxidative phosphorylation and cell senescence.Subsequently,lifespan assay and oxidative stress test were performed to investigate the peptides prepared from sea cucumber protein hydrolyzate using the aging model of Caenorhabditis elegans.The results of the anti-aging experiment demonstrated that high-dose peptides significantly prolonged the lifespan of nematodes(30.50%),and improved their capacity to inhibit oxidative stress.The results provide evidence supporting the development of bioactive proteins and peptides derived from Stichopus japonicus as functional foods and lay the foundation for the research of an anti-aging drug.展开更多
以初始体重为(6.77±0.01)g的仿刺参(Apostichopus japonicus Selenka)为实验对象,在基础饲料中添加1%不同分子量的壳聚糖,分子量分别为35 k Da和400 k Da,进行为期56 d的养殖实验,研究低分子壳聚糖(LMWC)和高分子壳聚糖(HMWC)对仿...以初始体重为(6.77±0.01)g的仿刺参(Apostichopus japonicus Selenka)为实验对象,在基础饲料中添加1%不同分子量的壳聚糖,分子量分别为35 k Da和400 k Da,进行为期56 d的养殖实验,研究低分子壳聚糖(LMWC)和高分子壳聚糖(HMWC)对仿刺参生长和免疫相关酶活性的影响。结果显示,不同分子量的壳聚糖对仿刺参的生长均有促进作用,且LMWC能显著促进刺参的特定生长率(SGR)(P<0.05)。饲料中添加不同分子量壳聚糖,刺参体腔细胞中的总超氧化物歧化酶(T-SOD)活性比对照组均显著增高(P<0.05)。LMWC可显著增强刺参体腔细胞中酸性磷酸酶(ACP)活性(P<0.05),并能提高碱性磷酸酶(AKP)和一氧化氮合酶(NOS)活性。HMWC对刺参体腔细胞中AKP和NOS活性均有显著增强作用(P<0.05)。研究表明,在刺参饲料中添加一定量的壳聚糖,对其生长和相关免疫酶活性有促进作用。展开更多
Sea cucumbers, Apostichopus japonicus Selenka, were fed diets containing non-immunostimulant (basal diet), 0.2% β-glucan and 0.02% glycyrrhizin in a recirculatory water system for 45 days, and subsequently challenged...Sea cucumbers, Apostichopus japonicus Selenka, were fed diets containing non-immunostimulant (basal diet), 0.2% β-glucan and 0.02% glycyrrhizin in a recirculatory water system for 45 days, and subsequently challenged with Vibrio splendidus by injection at 1.0×108 cfu/sea cucumber for 15 days.Phagocytic capacity (PC), intracellular superoxide anion production (ISAP), ly-sozyme (LSZ) activity and superoxide dismutase (SOD) activity in the coelomic fluid were analyzed on the 0th, 5th, 10th and 15th days after injection.Results showed that after the 45-day feeding period, PC, ISAP, LSZ activity and SOD activity in sea cucumbers fed with dietary β-glucan or glycyrrhizin were significantly higher than in those fed with the basal diet.On the 5th day after infection, all the immune parameters examined in the sea cucumbers injected with V.splendidus decreased in value significantly.On the 15th day, PC, ISAP and LSZ activity returned to levels similar to those on the 0th day.For the sea cucumbers injected with saline, there were no significant differences in all the immune parameters examined and in the cumulative morbidity during the 15-day challenging trial.After injecting with V.splendidus, the cumulative morbidity of sea cucumbers fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin when challenged with V.splendidus challenged sea cucumber fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin.There was no significant difference in cumulative morbidity between the dietary β-glucan and glycyrrhizin treatments over time.展开更多
The growth, metabolism and physiological response of the sea cucumber, Apostichopus japonicus, were investigated during periods of inactivity. The body weight, oxygen consumption rate (OCR), activities of acidic phosp...The growth, metabolism and physiological response of the sea cucumber, Apostichopus japonicus, were investigated during periods of inactivity. The body weight, oxygen consumption rate (OCR), activities of acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD), and content of heat shock protein 70 (Hsp70) in the body wall and coelomic fluid of A. japonicus were measured during starvation, experimental aestivation and aestivation. The results showed that the body weight of sea cucumber in the three treatments decreased significantly during the experimental period (P < 0.05). The OCR of sea cucumber reduced in starvation and experimental aestivation treatments, but increased gradually in natural aestivation treatment. The activities of ACP and AKP of sea cucumber decreased gradually in all treatments, whereas those of SOD and CAT as well as Hsp70 content decreased in the starvation and experimental aestivation treatments and increased in natural aestivation treatment. The sea cucumber entered a state of aestivation at 24℃. To some extent, the animals in experimental aestivation were different from those in natural aestivation in metabolism and physiological response. These findings suggested that the aestivation mechanism of A. japonicus is complex and may not be attributed to the elevated temperature only.展开更多
Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress...Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels （0.5, 1.0, and 1.5 mg/L） of nitrite stress for 4, 8, and 12 h at four time intervals （0, 15, 30, and 45 d）. Growth of the animals was recorded during the experiment. Reactive oxygen species （ROS） （i.e. hydroxyl free radical （-OH）, malondialdehyde （MDA） and total antioxidant capacity （T-AOC）） and antioxidant enzyme activities （i.e., superoxide dismutase （SOD） and eatalase （CAT）） were measured. Response surface methodology （RSM） was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain （WG） and special growth rate （SGR） of vitamin C supplementation groups were significantly higher than those of control group （P〈0.05）. The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.展开更多
The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopusjaponicus, including relative gut mass （RGM）, amylase, lipase, pepsin and trypsin activities were studied at temp...The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopusjaponicus, including relative gut mass （RGM）, amylase, lipase, pepsin and trypsin activities were studied at temperatures of 7, 14, 21, and 28℃ over a period of 40 days. Results show that RGM significantly decreased after 40 days at 21 ℃ and markedly decreased over the whole experiment period at 28℃; however, no significant effect of duration was observed at 7 or 14℃. At 14℃, trypsin activity significantly decreased over 10 and 20 days, then increased; amylase and trypsin activity significantly decreased after 40 days at 28℃. However, no significant effect of duration was found on amylase, pepsin or trypsin activities in the other temperature treatment groups. At 28℃, lipase activity peaked in 20 days and then markedly decreased to a minimum at the end of the experiment. On the other hand, pepsin activity at 28℃ continuously increased over the whole experimental period. Principle component analysis showed that sea cucumbers on day 40 in the 21℃ group and in the previous 20 days in the 28℃ group were in the prophase of aestivation. At 28℃, sea cucumbers aestivated at 30-40 days after the start of the experiment. It is concluded that the effect of temperature on the digestion ofA. japonicus is comparatively weak within a specific range of water temperatures and aestivation behavior is accompanied by significant changes in RGM and digestive enzyme activities.展开更多
In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval ...In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval length and density,metamorphic time,and survival rate of the larvae were recorded.Statistics showed that for A.japonicus,survival rate(from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature(P<0.05).At different temperatures SGR was statistically significant as well(P<0.05) from day 1,and maximal SGR was found on day 9 at 24℃(159.26±3.28).This study clearly indicated that at low temperature(<24℃),metamorphic rate was remarkably higher than at higher temperature(>26℃).Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups.Rearing larvae at the higher density had the smaller maximal-length,whereas needed longer time to complete metamorphosis.This study suggested that 21℃ and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large-scale artificial breeding of A.japonicus's larvae.展开更多
Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichop...Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichopus japonicus Selenka） to rapid temperature changes in laboratory. Animals were subjected to a higher temperature （from 10 to 20℃） （Tinc treatment） or to a lower temperature （from 20 to 10℃） （Tddec treatment） for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment.展开更多
The sea cucumber, Apostichopusjaponicus, undergoes aestivation to improve survival during periods of high-temperature. During aestivation, the metabolic rate is depressed to reduce the consumption of reserved energy. ...The sea cucumber, Apostichopusjaponicus, undergoes aestivation to improve survival during periods of high-temperature. During aestivation, the metabolic rate is depressed to reduce the consumption of reserved energy. We evaluated the role of epigenetic modification on global gene silencing during metabolic rate depression in the sea cucumber. We compared the expression of epigenetic modifiers in active and aestivating sea cucumbers. The expression of three genes involved in DNA methylation and chromatin remodeling （DNA （cytosine-5）-methyltransferase l, Methyl-CpG-binding domain protein 2）, and Chromodomain-helicase-DNA-binding protein 5） was significantly higher during aestivation （Days 20 and 40）. Similarly, we observed an increase in the expression of genes involved in histone acetylation （Histone deacetylase 3） and Histone-binding protein RBBP4） during the early （Days 5 and 10） and late phases （Days 20 and 40） of aestivation. There was no change in the expression of KAT2B, a histone acetyltransferase. However, the expression of histone methylation associated modifiers （Histone-arginine methyltransferase CARMER and Histone-lysine N-methyltransferase MLL5） was significantly higher after 5 d in the aestivating group. The results suggest that the expression of epigenetic modifiers involved in DNA methylation, chromatin remodeling, histone acetylation, and histone methylation is upregulated during aestivation. We hypothesize that these changes regulate global gene silencing during aestivation in A. japonicus.展开更多
The effects of Bacillus subtilis 2-1 from the intestine of healthy sea cucumber on the growth, digestive enzyme activities and intestinal microbiota of juvenile sea cucumber(Apostichopus japonicus) were determined in ...The effects of Bacillus subtilis 2-1 from the intestine of healthy sea cucumber on the growth, digestive enzyme activities and intestinal microbiota of juvenile sea cucumber(Apostichopus japonicus) were determined in the present study. Sea cucumber was fed with Sargassum thunbergii powder supplemented with B. subtilis 2-1 at different concentrations varying among 0(control), 10~5, 10~7, and 10~9 CFU g^(-1) for 8 weeks. Results showed that the growth performance and intestinal amylase and trypsin activities were significantly increased by dietary B. subtilis 2-1 at 10~9 CFU g^(-1)(P < 0.05). However, dietary B. subtilis 2-1 had no significant influence on the lipase activity in sea cucumber(P > 0.05). The polymerase chain reaction denaturing gradient gel electrophoresis and 16S rRNA gene sequencing analysis indicated that dietary B. subtilis 2-1 at 105 and 107 CFU g^(-1) inhibited most of the Proteobacteria including those in genus Vibrio. Dietary B. subtilis 2-1 at 10~9 CFU g^(-1) not only decreased the abundance and species of genus Vibrio, but also increased the intensity of genera Psychrobacter and Bacillus. A specific dosage of dietary B. subtilis 2-1 could increase the growth and modulate the intestinal microbiota of sea cucumber; thus it might be a novel probiotic for keeping the health of sea cucumber.展开更多
Albino Apostichopus japonicus occur both in the wild and in captivity. The offspring of albino A. japonicus also suffer from albinism. The formation of melanin in the melanocytes is dependant on microphthalmia-associa...Albino Apostichopus japonicus occur both in the wild and in captivity. The offspring of albino A. japonicus also suffer from albinism. The formation of melanin in the melanocytes is dependant on microphthalmia-associated transcription factor (MITF). To investigate the role of MITF in controlling albinism, we cloned the full-length MITF cDNA from A. japonicus and compared MITF mRNA expression in albino and normal A. japonicus. In addition, we used light and electron microscopy to compare histological samples of normal and albino A. japonicus. The body wall of albino adults was characterized by significantly lower levels of MITF expression and lower numbers of epidermal melanocytes, which also contained less melanin. In albino juvenile offspring, MITF expression levels were significantly lower 32 d after fertilization and there were fewer, and less developed, epidermal melanocytes. Thus, we conclude that albino A. japonicus have fewer melanocytes and a reduced ability to synthesize melanin, likely because of lower expression of MITF.展开更多
基金supported by the Subject of Key R&D Plan of Shandong Province(Major Scientific and Technological Innovation Project)“Mining and Accurate Identification of Forest Tree Germplasm Resources”(Grant Nos.2021LZGC02303)Science&Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta(Grant No.022SZX16)。
文摘VIGS(Virus-induced gene silencing),a method for posttranscriptional gene silencing,is an effective technique for investigating the activities of genes in plants.Since there is no report for available VIGS system in Styrax japonicus,the application of a VIGS approach that results in a gene knockdown to study gene function is limited.In this study,we compared the characteristics that could affect the viability of VIGS in S.japonicus,including the acetosyringone(AS)concentration,the Agrobacterium’s optical density and the inoculation method.The stable reference genes of S.japonicus were selected to validate the gene’s knockdown by quantitative PCR.As a result,we successfully constructed 2 VIGS systems based on TRV virus:vacuum with AS concentration of 200μmol·L^(-1)and OD600of 0.5,and friction-osmosis with AS concentration of 200μmol·L^(-1)and OD600of 1.0,which silencing efficiency was 83.33%and 74.19%,respectively.The successfully applied VIGS method provides a rapid and effective reverse gene functional analysis approach in S.japonicus to identify unknown gene functions.
基金Supported by Scientific Research Program of Higher Education Institutions in Hainan Province(Hnky2019-110)Hainan Provincial Natural Science Foundation of China(424QN258)+1 种基金Hainan Provincial Key Point Research and Invention Program(ZDYF2022SHFZ309)Special Scientific Research Project of Hainan Academician Innovation Platform(YSPTZX202132).
文摘The sea cucumber Stichopus japonicus is one of the"Eight Treasures of Seafood"and contains a number of bioactive components involved in multiple physiological and pharmacological functions.Proteins and peptides are generally considered to be responsible for these beneficial properties.In this study,a total of 3478 proteins and 17390 peptides were identified in Stichopus japonicus by proteomics methods.Among them,4 proteins were involved in 8 metabolic pathways,especially oxidative phosphorylation and cell senescence.Subsequently,lifespan assay and oxidative stress test were performed to investigate the peptides prepared from sea cucumber protein hydrolyzate using the aging model of Caenorhabditis elegans.The results of the anti-aging experiment demonstrated that high-dose peptides significantly prolonged the lifespan of nematodes(30.50%),and improved their capacity to inhibit oxidative stress.The results provide evidence supporting the development of bioactive proteins and peptides derived from Stichopus japonicus as functional foods and lay the foundation for the research of an anti-aging drug.
文摘以初始体重为(6.77±0.01)g的仿刺参(Apostichopus japonicus Selenka)为实验对象,在基础饲料中添加1%不同分子量的壳聚糖,分子量分别为35 k Da和400 k Da,进行为期56 d的养殖实验,研究低分子壳聚糖(LMWC)和高分子壳聚糖(HMWC)对仿刺参生长和免疫相关酶活性的影响。结果显示,不同分子量的壳聚糖对仿刺参的生长均有促进作用,且LMWC能显著促进刺参的特定生长率(SGR)(P<0.05)。饲料中添加不同分子量壳聚糖,刺参体腔细胞中的总超氧化物歧化酶(T-SOD)活性比对照组均显著增高(P<0.05)。LMWC可显著增强刺参体腔细胞中酸性磷酸酶(ACP)活性(P<0.05),并能提高碱性磷酸酶(AKP)和一氧化氮合酶(NOS)活性。HMWC对刺参体腔细胞中AKP和NOS活性均有显著增强作用(P<0.05)。研究表明,在刺参饲料中添加一定量的壳聚糖,对其生长和相关免疫酶活性有促进作用。
基金supported by grant No.2006AA100313 from the National High Technology Research and Development Project of P.R. China (863 Project)
文摘Sea cucumbers, Apostichopus japonicus Selenka, were fed diets containing non-immunostimulant (basal diet), 0.2% β-glucan and 0.02% glycyrrhizin in a recirculatory water system for 45 days, and subsequently challenged with Vibrio splendidus by injection at 1.0×108 cfu/sea cucumber for 15 days.Phagocytic capacity (PC), intracellular superoxide anion production (ISAP), ly-sozyme (LSZ) activity and superoxide dismutase (SOD) activity in the coelomic fluid were analyzed on the 0th, 5th, 10th and 15th days after injection.Results showed that after the 45-day feeding period, PC, ISAP, LSZ activity and SOD activity in sea cucumbers fed with dietary β-glucan or glycyrrhizin were significantly higher than in those fed with the basal diet.On the 5th day after infection, all the immune parameters examined in the sea cucumbers injected with V.splendidus decreased in value significantly.On the 15th day, PC, ISAP and LSZ activity returned to levels similar to those on the 0th day.For the sea cucumbers injected with saline, there were no significant differences in all the immune parameters examined and in the cumulative morbidity during the 15-day challenging trial.After injecting with V.splendidus, the cumulative morbidity of sea cucumbers fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin when challenged with V.splendidus challenged sea cucumber fed with the basal diet was significantly higher than those fed with dietary β-glucan or glycyrrhizin.There was no significant difference in cumulative morbidity between the dietary β-glucan and glycyrrhizin treatments over time.
基金supported by the Natural Science Funds for Distinguished Young Scientists of Shandong Province (No.JQ201009)the National Great Project of Scientific and Technical Supporting Programs (No.2011-BAD13B03)+2 种基金the National Natural Science Foundation of China (No.30771661)the Public Science and Technology Research Funds Projects of Ocean, State Oceanic Administration of China (No.200905020)the 111 Project of China Ministry of Education (No.B08049)
文摘The growth, metabolism and physiological response of the sea cucumber, Apostichopus japonicus, were investigated during periods of inactivity. The body weight, oxygen consumption rate (OCR), activities of acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD), and content of heat shock protein 70 (Hsp70) in the body wall and coelomic fluid of A. japonicus were measured during starvation, experimental aestivation and aestivation. The results showed that the body weight of sea cucumber in the three treatments decreased significantly during the experimental period (P < 0.05). The OCR of sea cucumber reduced in starvation and experimental aestivation treatments, but increased gradually in natural aestivation treatment. The activities of ACP and AKP of sea cucumber decreased gradually in all treatments, whereas those of SOD and CAT as well as Hsp70 content decreased in the starvation and experimental aestivation treatments and increased in natural aestivation treatment. The sea cucumber entered a state of aestivation at 24℃. To some extent, the animals in experimental aestivation were different from those in natural aestivation in metabolism and physiological response. These findings suggested that the aestivation mechanism of A. japonicus is complex and may not be attributed to the elevated temperature only.
基金Supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(No.KZCX2-EWQ215)
文摘Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels （0.5, 1.0, and 1.5 mg/L） of nitrite stress for 4, 8, and 12 h at four time intervals （0, 15, 30, and 45 d）. Growth of the animals was recorded during the experiment. Reactive oxygen species （ROS） （i.e. hydroxyl free radical （-OH）, malondialdehyde （MDA） and total antioxidant capacity （T-AOC）） and antioxidant enzyme activities （i.e., superoxide dismutase （SOD） and eatalase （CAT）） were measured. Response surface methodology （RSM） was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain （WG） and special growth rate （SGR） of vitamin C supplementation groups were significantly higher than those of control group （P〈0.05）. The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.
基金Supported by the Science Fund for Creative Research Groups (No.40821004)National Natural Science Foundation of China (No.40576073)+1 种基金Breeding Project of Shandong Province (China),National Key Technology Research and Development Program of China (No. 2006BAD09A02)the National High Technology Research and Development Program of China (863 Program) (No.2006AA100304 /2006AA10A411)
文摘The effect of water temperature on gut mass and digestive enzyme activity in sea cucumber Apostichopusjaponicus, including relative gut mass （RGM）, amylase, lipase, pepsin and trypsin activities were studied at temperatures of 7, 14, 21, and 28℃ over a period of 40 days. Results show that RGM significantly decreased after 40 days at 21 ℃ and markedly decreased over the whole experiment period at 28℃; however, no significant effect of duration was observed at 7 or 14℃. At 14℃, trypsin activity significantly decreased over 10 and 20 days, then increased; amylase and trypsin activity significantly decreased after 40 days at 28℃. However, no significant effect of duration was found on amylase, pepsin or trypsin activities in the other temperature treatment groups. At 28℃, lipase activity peaked in 20 days and then markedly decreased to a minimum at the end of the experiment. On the other hand, pepsin activity at 28℃ continuously increased over the whole experimental period. Principle component analysis showed that sea cucumbers on day 40 in the 21℃ group and in the previous 20 days in the 28℃ group were in the prophase of aestivation. At 28℃, sea cucumbers aestivated at 30-40 days after the start of the experiment. It is concluded that the effect of temperature on the digestion ofA. japonicus is comparatively weak within a specific range of water temperatures and aestivation behavior is accompanied by significant changes in RGM and digestive enzyme activities.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2006AA10A411)Shandong Agriculture Seed Stock Projects
文摘In laboratory conditions,effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively.Data series like larval length and density,metamorphic time,and survival rate of the larvae were recorded.Statistics showed that for A.japonicus,survival rate(from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature(P<0.05).At different temperatures SGR was statistically significant as well(P<0.05) from day 1,and maximal SGR was found on day 9 at 24℃(159.26±3.28).This study clearly indicated that at low temperature(<24℃),metamorphic rate was remarkably higher than at higher temperature(>26℃).Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups.Rearing larvae at the higher density had the smaller maximal-length,whereas needed longer time to complete metamorphosis.This study suggested that 21℃ and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large-scale artificial breeding of A.japonicus's larvae.
文摘Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichopus japonicus Selenka） to rapid temperature changes in laboratory. Animals were subjected to a higher temperature （from 10 to 20℃） （Tinc treatment） or to a lower temperature （from 20 to 10℃） （Tddec treatment） for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment.
基金Supported by the National Key Technology Research and Development Program(No.2006AA10A411)the Agricultural Seed Project of Shandong Province
文摘The sea cucumber, Apostichopusjaponicus, undergoes aestivation to improve survival during periods of high-temperature. During aestivation, the metabolic rate is depressed to reduce the consumption of reserved energy. We evaluated the role of epigenetic modification on global gene silencing during metabolic rate depression in the sea cucumber. We compared the expression of epigenetic modifiers in active and aestivating sea cucumbers. The expression of three genes involved in DNA methylation and chromatin remodeling （DNA （cytosine-5）-methyltransferase l, Methyl-CpG-binding domain protein 2）, and Chromodomain-helicase-DNA-binding protein 5） was significantly higher during aestivation （Days 20 and 40）. Similarly, we observed an increase in the expression of genes involved in histone acetylation （Histone deacetylase 3） and Histone-binding protein RBBP4） during the early （Days 5 and 10） and late phases （Days 20 and 40） of aestivation. There was no change in the expression of KAT2B, a histone acetyltransferase. However, the expression of histone methylation associated modifiers （Histone-arginine methyltransferase CARMER and Histone-lysine N-methyltransferase MLL5） was significantly higher after 5 d in the aestivating group. The results suggest that the expression of epigenetic modifiers involved in DNA methylation, chromatin remodeling, histone acetylation, and histone methylation is upregulated during aestivation. We hypothesize that these changes regulate global gene silencing during aestivation in A. japonicus.
基金supported by the National Natural Science Foundation of China (Nos.31202004,31402304)PhD Programs Foundation of Ludong University (No.LY2012009)the Open Fund of the Key Laboratory of Marine Biotech of Guangxi (No.GLMBT-201205)
文摘The effects of Bacillus subtilis 2-1 from the intestine of healthy sea cucumber on the growth, digestive enzyme activities and intestinal microbiota of juvenile sea cucumber(Apostichopus japonicus) were determined in the present study. Sea cucumber was fed with Sargassum thunbergii powder supplemented with B. subtilis 2-1 at different concentrations varying among 0(control), 10~5, 10~7, and 10~9 CFU g^(-1) for 8 weeks. Results showed that the growth performance and intestinal amylase and trypsin activities were significantly increased by dietary B. subtilis 2-1 at 10~9 CFU g^(-1)(P < 0.05). However, dietary B. subtilis 2-1 had no significant influence on the lipase activity in sea cucumber(P > 0.05). The polymerase chain reaction denaturing gradient gel electrophoresis and 16S rRNA gene sequencing analysis indicated that dietary B. subtilis 2-1 at 105 and 107 CFU g^(-1) inhibited most of the Proteobacteria including those in genus Vibrio. Dietary B. subtilis 2-1 at 10~9 CFU g^(-1) not only decreased the abundance and species of genus Vibrio, but also increased the intensity of genera Psychrobacter and Bacillus. A specific dosage of dietary B. subtilis 2-1 could increase the growth and modulate the intestinal microbiota of sea cucumber; thus it might be a novel probiotic for keeping the health of sea cucumber.
基金Supported by the National Natural Science Foundation of China(No. 40976089)the National Marine Public Welfare Research Project(No. 200805069)+1 种基金the National Science and Technology Support Program of China (No. 2011BAD13B02)the Breeding Project of Shandong Province (China)
文摘Albino Apostichopus japonicus occur both in the wild and in captivity. The offspring of albino A. japonicus also suffer from albinism. The formation of melanin in the melanocytes is dependant on microphthalmia-associated transcription factor (MITF). To investigate the role of MITF in controlling albinism, we cloned the full-length MITF cDNA from A. japonicus and compared MITF mRNA expression in albino and normal A. japonicus. In addition, we used light and electron microscopy to compare histological samples of normal and albino A. japonicus. The body wall of albino adults was characterized by significantly lower levels of MITF expression and lower numbers of epidermal melanocytes, which also contained less melanin. In albino juvenile offspring, MITF expression levels were significantly lower 32 d after fertilization and there were fewer, and less developed, epidermal melanocytes. Thus, we conclude that albino A. japonicus have fewer melanocytes and a reduced ability to synthesize melanin, likely because of lower expression of MITF.
