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Huai Ping Zheng - One of the best experts on this subject based on the ideXlab platform.

  • construction of genetic map and qtl analysis of carotenoid related trait based on est markers in noble scallop Chlamys Nobilis
    Aquaculture, 2021
    Co-Authors: Fang Meng, Karsoon Tan, Guofan Zhang, Huai Ping Zheng
    Abstract:

    Abstract Carotenoid is an important economic trait for genetic and breeding in animals and plants. The noble scallop Chlamys Nobilis is an important aquaculture bivalve in southern China. Studies in the noble scallop have shown that carotenoids content among individuals in their muscle are varies. In order to explain the variation, a genetic map was constructed in this study using F2 progenies with different carotenoids content, and then QTLs for carotenoids content in adductor and mantle were analyzed. Totally, 225 polymorphic markers (170 SNPs, 32 InDels and 23 SSRs) were developed from expressed sequence tags (ESTs). The female map had 16 linkage groups and spanned 595.2 cM with an average interval of 6.7 cM, and the male map had 19 linkage groups and spanned 745.7 cM with an average interval of 7.2 cM. However, the integrated map only contained 14 linkage groups, spanning 691.2 cM and with an average interval of 4.8 cM. A total of five QTLs were identified including three in the adductor and two in the mantle, which were distributed in linkage group 1 (Z1), 5 (Z5) and 12 (Z12), respectively. In addition, two QTLs on Z12 completely overlapped, which explained 28.0% in the adductor and 55.6% in the mantle of phenotypic variation, respectively, suggesting the presence of important carotenoid-determining genes in this region. The present study was the first to construct a genetic map using animals with different carotenoids content and identified five QTLs for carotenoids content, which can provide new insights for further understanding genetic mechanism of carotenoids deposition.

  • genome wide analysis of traf gene family and its response to bacterial infection in noble scallop Chlamys Nobilis with different carotenoids content
    Aquaculture, 2021
    Co-Authors: Hongkuan Zhang, Karsoon Tan, Huai Ping Zheng
    Abstract:

    Abstract Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are multifunctional adaptor proteins in the immune system, which play significant roles in the regulation of Toll-like receptor and RIG-I-like receptor signaling pathway in animals. Although many TRAF genes have been identified in mollusks, the systematic identification of the TRAF gene family in noble scallop Chlamys Nobilis has not been reported, and very little is known about its roles in scallop innate immunity. In this study, four TRAF genes (CnTRAF 2, CnTRAF3, CnTRAF4 and CnTRAF6) were identified and characterized from C. Nobilis. Sequence and phylogenetic analysis revealed that CnTRAFs contain typical conserved domains closely related to TRAFs of other mollusks. The motifs analysis of C. Nobilis CnTRAFs also showed that the conserved motifs were identical to other mollusks and vertebrates. The expression pattern of CnTRAF genes in tissues of brown and golden scallops (the carotenoid content of golden scallops is significantly higher than that of brown scallops) were not statistically significant, but in hemolymph of scallops challenged with bacteria, the expression of CnTRAF genes was significantly higher than that of control, suggesting that the CnTRAF genes play vital roles in the immunity of mollusks. Furthermore, at several time points after bacteria challenge, the expression level of CnTRAF genes in golden scallops were significantly higher than that of brown scallops, indicating that carotenoids may enhance CnTRAF genes expression and immunity. The systematic analysis of the roles of TRAFs in C. Nobilis provides valuable information for the further researches of CnTRAF genes.

  • carotenoids regulation in polymorphic noble scallops Chlamys Nobilis under different light cycle
    Aquaculture, 2021
    Co-Authors: Karsoon Tan, Hongkuan Zhang, Zhicheng Guo, Huai Ping Zheng
    Abstract:

    Abstract Light cycle is an important factor affecting the total carotenoid content (TCC) in tissues of noble scallops Chlamys Nobilis, but its regulatory mechanism is still unclear. In this study, adult polymorphic C. Nobilis (Nan'ao Golden Scallop and common brown scallop) were exposed to three different light cycles (24L/0D, 12L/12D and 0L/24D) for 10 days. The expression of carotenoid related genes (Scavenger Receptor class B (SRB) genes, β-carotene oxygenase (BCO) genes, and Retinoic acid receptors (RAR and RXR) genes) were determined by qRT-PCR. The results revealed that 24L/0D and 0L/24D treatments significantly increased the accumulation of TCC in adductor muscle of Nan'ao Golden Scallop and common brown scallop, respectively. The deposition of carotenoids in adductor muscle was induced by the up-regulation of SRB genes, of which was then up-regulation of BCO gene expression, followed by the up-regulation of RAR and/or RXR expression, and then further induced the expression of SRB and BCO genes. In hemolymph, the absorption mechanism of carotenoids may not involve SRB genes, or other carotenoid related genes may mask the role of SRB genes. The findings of this study provide important clues for further understanding the mechanism of TCC accumulation in polymorphic C. Nobilis under different light cycle.

  • potential causative factors of noble scallop Chlamys Nobilis mass mortality in nan ao island shantou china in 2017
    Science of The Total Environment, 2021
    Co-Authors: Karsoon Tan, Hongkuan Zhang, Huai Ping Zheng
    Abstract:

    Abstract Noble scallop Chlamys Nobilis is an important marine bivalve that has been extensively cultured in the south coast of China since the 1980s. Unfortunately, since the late 1990s, the farmed scallops often suffered from regional mass mortality, which results in enormous economic losses to farmers and industries. In 2017, another mass mortality event occurred in Nan'ao Island, Shantou, China. In this study, the cause of C. Nobilis mass mortality in 2017 was first investigated in the field, and then validated in a laboratory experiment. In the field, three sampling sites were selected according to the scallop mortality rate: Hunter Bay (90% mortality), Baisha Bay (67% mortality) and Longhai (6% mortality). Meanwhile, environmental parameters (temperature, salinity, DO, pH and chlorophyll a) of each site were also measured in situ. Then, water and scallop samples were collected randomly for the analysis of phytoplankton diversity and algal toxin activity using 18S rDNA and PP2A inhibition assay, respectively. In laboratory, healthy scallops were challenged with Karenia mikimotoi (1 × 103 cells/mL) for 30 h. The field results showed that no significant difference in those environmental parameters existed among the three sites, but the relative abundance of K. mikimotoi in seawater and scallops' intestines in Hunter Bay and Baisha Bay was significantly higher than that in Longhai, and sick scallops contained significantly higher algal toxin activity than healthy ones. Laboratory results revealed that challenged scallops with K. mikimotoi showed significantly higher mortality rate and algal toxin activity than healthy ones, and low density of K. mikimotoi (1 × 103 cells/mL) was sufficient to cause >50% scallops' mortality within 26 h. This study provides the first evidence that low K. mikimotoi cell density can cause massive mortality in C. Nobilis, and provides useful information as guide to prevent scallop mass mortality in the future.

  • a novel carotenoids producing marine bacterium from noble scallop Chlamys Nobilis and antioxidant activities of its carotenoid compositions
    Food Chemistry, 2020
    Co-Authors: Hongxing Liu, Karsoon Tan, Hongkuan Zhang, Dewei Cheng, Chuanxu Zhang, Xinxu Zhang, Huai Ping Zheng
    Abstract:

    Abstract Marine bacteria produce many bioactive compounds, including carotenoids. However, the quality of bacterium carotenoids is relatively unknown. Therefore, in this study, a novel carotenoids-producing bacterium Brevundimonas scallop Zheng & Liu was isolated from Chlamys Nobilis. The genome of the isolate was analyzed, carotenoid compounds were screened using HPLC-MS and the carotenoid production in B. scallop was monitored. The results revealed that the genome of B. scallop contained a carotenoid synthesis gene cluster, which involved in astaxanthin and hydroxy-astaxanthin biosynthesis. The 2,2′-dihydroxy-astaxanthin was the major carotenoid produced by B. scallop. The optimum culture condition for the highest carotenoids production (1303.62 ± 61.06 µg/g dry cells) for B. scallop was at temperature and salinity of 20 °C and 3% salt, respectively, in 10 g/L glucose as carbon source. The results showed the B. scallop is a new carotenoids resource in marine bivalve, which has an excellent antioxidative activity and potential industrial use.

Hongkuan Zhang - One of the best experts on this subject based on the ideXlab platform.

  • genome wide analysis of traf gene family and its response to bacterial infection in noble scallop Chlamys Nobilis with different carotenoids content
    Aquaculture, 2021
    Co-Authors: Hongkuan Zhang, Karsoon Tan, Huai Ping Zheng
    Abstract:

    Abstract Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are multifunctional adaptor proteins in the immune system, which play significant roles in the regulation of Toll-like receptor and RIG-I-like receptor signaling pathway in animals. Although many TRAF genes have been identified in mollusks, the systematic identification of the TRAF gene family in noble scallop Chlamys Nobilis has not been reported, and very little is known about its roles in scallop innate immunity. In this study, four TRAF genes (CnTRAF 2, CnTRAF3, CnTRAF4 and CnTRAF6) were identified and characterized from C. Nobilis. Sequence and phylogenetic analysis revealed that CnTRAFs contain typical conserved domains closely related to TRAFs of other mollusks. The motifs analysis of C. Nobilis CnTRAFs also showed that the conserved motifs were identical to other mollusks and vertebrates. The expression pattern of CnTRAF genes in tissues of brown and golden scallops (the carotenoid content of golden scallops is significantly higher than that of brown scallops) were not statistically significant, but in hemolymph of scallops challenged with bacteria, the expression of CnTRAF genes was significantly higher than that of control, suggesting that the CnTRAF genes play vital roles in the immunity of mollusks. Furthermore, at several time points after bacteria challenge, the expression level of CnTRAF genes in golden scallops were significantly higher than that of brown scallops, indicating that carotenoids may enhance CnTRAF genes expression and immunity. The systematic analysis of the roles of TRAFs in C. Nobilis provides valuable information for the further researches of CnTRAF genes.

  • carotenoids regulation in polymorphic noble scallops Chlamys Nobilis under different light cycle
    Aquaculture, 2021
    Co-Authors: Karsoon Tan, Hongkuan Zhang, Zhicheng Guo, Huai Ping Zheng
    Abstract:

    Abstract Light cycle is an important factor affecting the total carotenoid content (TCC) in tissues of noble scallops Chlamys Nobilis, but its regulatory mechanism is still unclear. In this study, adult polymorphic C. Nobilis (Nan'ao Golden Scallop and common brown scallop) were exposed to three different light cycles (24L/0D, 12L/12D and 0L/24D) for 10 days. The expression of carotenoid related genes (Scavenger Receptor class B (SRB) genes, β-carotene oxygenase (BCO) genes, and Retinoic acid receptors (RAR and RXR) genes) were determined by qRT-PCR. The results revealed that 24L/0D and 0L/24D treatments significantly increased the accumulation of TCC in adductor muscle of Nan'ao Golden Scallop and common brown scallop, respectively. The deposition of carotenoids in adductor muscle was induced by the up-regulation of SRB genes, of which was then up-regulation of BCO gene expression, followed by the up-regulation of RAR and/or RXR expression, and then further induced the expression of SRB and BCO genes. In hemolymph, the absorption mechanism of carotenoids may not involve SRB genes, or other carotenoid related genes may mask the role of SRB genes. The findings of this study provide important clues for further understanding the mechanism of TCC accumulation in polymorphic C. Nobilis under different light cycle.

  • potential causative factors of noble scallop Chlamys Nobilis mass mortality in nan ao island shantou china in 2017
    Science of The Total Environment, 2021
    Co-Authors: Karsoon Tan, Hongkuan Zhang, Huai Ping Zheng
    Abstract:

    Abstract Noble scallop Chlamys Nobilis is an important marine bivalve that has been extensively cultured in the south coast of China since the 1980s. Unfortunately, since the late 1990s, the farmed scallops often suffered from regional mass mortality, which results in enormous economic losses to farmers and industries. In 2017, another mass mortality event occurred in Nan'ao Island, Shantou, China. In this study, the cause of C. Nobilis mass mortality in 2017 was first investigated in the field, and then validated in a laboratory experiment. In the field, three sampling sites were selected according to the scallop mortality rate: Hunter Bay (90% mortality), Baisha Bay (67% mortality) and Longhai (6% mortality). Meanwhile, environmental parameters (temperature, salinity, DO, pH and chlorophyll a) of each site were also measured in situ. Then, water and scallop samples were collected randomly for the analysis of phytoplankton diversity and algal toxin activity using 18S rDNA and PP2A inhibition assay, respectively. In laboratory, healthy scallops were challenged with Karenia mikimotoi (1 × 103 cells/mL) for 30 h. The field results showed that no significant difference in those environmental parameters existed among the three sites, but the relative abundance of K. mikimotoi in seawater and scallops' intestines in Hunter Bay and Baisha Bay was significantly higher than that in Longhai, and sick scallops contained significantly higher algal toxin activity than healthy ones. Laboratory results revealed that challenged scallops with K. mikimotoi showed significantly higher mortality rate and algal toxin activity than healthy ones, and low density of K. mikimotoi (1 × 103 cells/mL) was sufficient to cause >50% scallops' mortality within 26 h. This study provides the first evidence that low K. mikimotoi cell density can cause massive mortality in C. Nobilis, and provides useful information as guide to prevent scallop mass mortality in the future.

  • a novel carotenoids producing marine bacterium from noble scallop Chlamys Nobilis and antioxidant activities of its carotenoid compositions
    Food Chemistry, 2020
    Co-Authors: Hongxing Liu, Karsoon Tan, Hongkuan Zhang, Dewei Cheng, Chuanxu Zhang, Xinxu Zhang, Huai Ping Zheng
    Abstract:

    Abstract Marine bacteria produce many bioactive compounds, including carotenoids. However, the quality of bacterium carotenoids is relatively unknown. Therefore, in this study, a novel carotenoids-producing bacterium Brevundimonas scallop Zheng & Liu was isolated from Chlamys Nobilis. The genome of the isolate was analyzed, carotenoid compounds were screened using HPLC-MS and the carotenoid production in B. scallop was monitored. The results revealed that the genome of B. scallop contained a carotenoid synthesis gene cluster, which involved in astaxanthin and hydroxy-astaxanthin biosynthesis. The 2,2′-dihydroxy-astaxanthin was the major carotenoid produced by B. scallop. The optimum culture condition for the highest carotenoids production (1303.62 ± 61.06 µg/g dry cells) for B. scallop was at temperature and salinity of 20 °C and 3% salt, respectively, in 10 g/L glucose as carbon source. The results showed the B. scallop is a new carotenoids resource in marine bivalve, which has an excellent antioxidative activity and potential industrial use.

  • identification and molecular characterization of peroxiredoxin 6 from noble scallop Chlamys Nobilis revealing its potent immune response and antioxidant property
    Fish & Shellfish Immunology, 2020
    Co-Authors: Dewei Cheng, Karsoon Tan, Hongkuan Zhang, Hongxing Liu, Xinxu Zhang, Huai Ping Zheng
    Abstract:

    Abstract The 1-cyseine peroxiredoxin (Prx6) is an importantly antioxidant enzyme that protects cells from oxidative damage caused by excessive production of reactive oxygen species (ROS). In this study, we described the molecular characteristics of the noble scallop Chlamys Nobilis peroxiredoxin 6 (designed as CnPrx6), immune responses and DNA protection activity of the recombinant protein. The complete ORF (696 bp) of CnPrx6 encoded a polypeptide (25.5 kDa) of 231 amino acids, harboring a conserved peroxidase catalytic center (41PVCTTE46) and the catalytic triads putatively involved in peroxidase and phospholipase A2 activities. The deduced amino acid sequence of CnPrx6 shared a relatively high amino acid sequence similarity (more than 50%). The qRT-PCR revealed that the CnPrx6 mRNA was constitutively expressed in all examined tissues, with the highest expression observed in adductor. Upon immunological challenge with Vibrio parahaemolyticus, lipopolysaccharides (LPS) and polyinosinic-polycytidylic acid (Poly I:C), the expression level of CnPrx6 mRNA was significantly up-regulated (P

Helu Liu - One of the best experts on this subject based on the ideXlab platform.

  • Seasonal variation of total carotenoids content in the tissues of male and female golden noble scallops Chlamys Nobilis
    'Elsevier BV', 2020
    Co-Authors: Helu Liu, Hong Kua Zhang, Lim, Leong Seng, Hongyu Ma, Huai Ping Zheng
    Abstract:

    The noble scallop Chlamys Nobilis is an economically important edible marine bivalve that has been cultivated in the Southern Sea of China since the 1980s. Noble scallops, particularly the golden scallops, are rich in carotenoids, are of interest for their potential beneficial uses in human healthcare, food processing and pharmaceuticals. However, very little is known about the seasonal variation of total carotenoids content (TCC) in the golden scallops. Therefore, present study was conducted to determine the seasonal variation of TCC in the tissues of male and female of golden scallops. The results of present study revealed that the TCC in adductor, mantle and gonads of golden scallops were ranged from 16.79 to 138.86 μg/ g, 92.86 to 312.98 μg/ g, and 71.5 to 750.0 μg/ g, respectively. Generally, the gonads of golden scallops contain the highest TCC, followed by the mantle and adductor. In comparison of male and female scallops, TCC in the same tissue (except for gonad) was not statistically significant. However, female gonads contain much higher TCC than male gonads. The temporal variation of the TCC in golden scallops showed the highest in March to April and the lowest in October. The findings of current study can be very useful for scallop farmers and industry to determine the best harvest time to obtain the highest quality of golden scallops with high TCC

  • regulatory roles of sterol regulatory element binding protein srebp on lipid metabolism in marine invertebrate Chlamys Nobilis
    Aquaculture, 2018
    Co-Authors: Helu Liu, Hongkuan Zhang, Huai Ping Zheng
    Abstract:

    Abstract Sterol regulatory element-binding protein (SREBP) has mainly been studied in vertebrates in which lipogenesis is regulated in both liver and adipose tissue. There is, however, a paucity of information on bivalves, in which lipogenesis occurs essentially in ovary. To investigate the regulatory roles of SREBP on lipid metabolism in mollusks, the cDNA of scallop Chlamys Nobilis was sequenced, its expression in different tissues and different developmental ovary stages was studied, and effect of 17β-estradiol (E2) on CnSREBP in ovary was investigated. The predicted scallop SREBP contains a conserved helix-loop-helix domain and a leucine zipper (bHLH-Zip) region, however, the amino acid sequence only shows a 39–45% identity with vertebrate. Phylogenetic tree analysis showed that the putative scallop SREBP (CnSREBP) clustered separately with invertebrate SREBP-1 and SREBP-2. There is a significantly positive correlation between CnSREBP expression level and lipid content in tissues (r = 0.9705, P

  • differential expression of cuznsod gene under low temperature stress in noble scallop Chlamys Nobilis with different carotenoid content
    Fish & Shellfish Immunology, 2016
    Co-Authors: Jianqiao Han, Helu Liu, Huai Ping Zheng, Huajuan Deng, Bo Zhang
    Abstract:

    The noble scallop Chlamys Nobilis belongs to a warm-water mollusk and has been cultured in the sea of southern China since 1980s'. However, accidents of massive mortality have often occurred during the winter, and one of the reasons could be accumulation of harmful reactive oxygen species caused by lower temperature. Carotenoids are well known for their anti-oxidant function. To investigate whether carotenoids do play a role in mollusks' antioxidant defense system under lower temperature stress, an acute lower temperature experiment was conducted by using two types of scallops: the orange with higher carotenoids content and the brown with lower carotenoids content. Their CuZnSOD gene was cloned, mRNA expression levels were determined, and SOD activity and carotenoids content were measured. The complete CuZnSOD cDNA consists of 1078 nucleotides with an open reading frame encoding 154 amino acid residues, which has high identity with that of its sister species Chlamys farreri. The mRNA expression levels in both the mantle and gill from the orange scallops were significantly higher (P < 0.05) than that of the brown ones, but the result was the opposite in the blood. SOD activity in the mantle and gill from the orange scallops was significantly higher than (P < 0.05) that from the brown ones. Further, significantly positive correlations were found among CuZnSOD gene transcript levels, SOD activity and total carotenoids content in the orange scallops. The present results suggested that carotenoids could play roles in antioxidant defense system by upregulating gene expression under lower temperature stress in the noble scallop.

  • differential immune response of vitellogenin gene to vibrio anguillarum in noble scallop Chlamys Nobilis and its correlation with total carotenoid content
    Fish & Shellfish Immunology, 2016
    Co-Authors: Qian Zhang, Huai Ping Zheng, Helu Liu
    Abstract:

    Vitellogenin (Vg), an egg yolk precursor protein, not only functions as a source of nutrients and a nonpolar molecular carrier that combine and transfer lipids, proteins, vitamin and carotenoids to oocytes during the oogenesis. but also links with the immune defense in many oviparous animals. To investigate whether Vg plays a immune defensive role in noble scallop Chlamys Nobilis, an acute Vibrio anguillarum infection experiment was conducted in orange and brown scallops with different carotenoids content. qRT-PCR result showed that Vg transcripts were significantly up-regulated after challenge with V. anguillarum in orange and brown shell scallops compared to the control group and Vg expression reached the highest spot at 6 h, indicated that Vg possessed an immune function in the noble scallop. Interestingly, a significantly positive correlation between Vg transcript levels and total carotenoids content in the ovary was observed, indicating that Vg gene expression was up regulated by carotenoids. The results suggest that Vg is a potent immune protector and carotenoid may linked with Vg plays an important role in host immune system against pathogens in noble scallop C. Nobilis.

  • a de novo transcriptome of the noble scallop Chlamys Nobilis focusing on mining transcripts for carotenoid based coloration
    BMC Genomics, 2015
    Co-Authors: Helu Liu, Huai Ping Zheng, Wenhua Liu, Hongkuan Zhang, Longhui Deng, Shuqi Wang, Fang Meng, Yajun Wang, Zhicheng Guo
    Abstract:

    The noble scallop Chlamys Nobilis Reeve displays polymorphism in shell and muscle colors. Previous research showed that the orange scallops with orange shell and muscle had a significantly higher carotenoid content than the brown ones with brown shell and white muscle. There is currently a need to identify candidate genes associated with carotenoid-based coloration. In the present study, 454 GS-FLX sequencing of noble scallop transcriptome yielded 1,181,060 clean sequence reads, which were assembled into 49,717 isotigs, leaving 110,158 reads as the singletons. Of the 159,875 unique sequences, 11.84% isotigs and 9.35% singletons were annotated. Moreover, 3,844 SSRs and over 120,000 high confidence variants (SNPs and INDELs) were identified. Especially, one class B scavenge receptor termed SRB-like-3 was discovered to express only in orange scallops and absent in brown ones, suggesting a significant association with high carotenoid content. Down-regulation of SRB-like-3 mRNA by RNA interference remarkably decreased blood carotenoid, providing compelling evidence that SRB-like-3 is an ideal candidate gene controlling carotenoid deposition and determining orange coloration. Transcriptome analysis of noble scallop reveals a novel scavenger receptor significantly associated with orange scallop rich in carotenoid content. Our findings pave the way for further functional elucidation of this gene and molecular basis of carotenoid deposition in orange scallop.

Wenxiong Wang - One of the best experts on this subject based on the ideXlab platform.

  • mercury accumulation in marine bivalves influences of biodynamics and feeding niche
    Environmental Pollution, 2011
    Co-Authors: Ke Pan, Wenxiong Wang
    Abstract:

    Abstract Differences in the accumulation of mercury (Hg) in five species of marine bivalves, including scallops Chlamys Nobilis , clams Ruditapes philippinarum , oysters Saccostrea cucullata , green mussels Perna viridis , and black mussels Septifer virgatus , were investigated. The bivalves displayed different patterns of Hg accumulation in terms of the body concentrations of methylmercury (MeHg) and total Hg (THg), as well as the ratio of MeHg to THg. Parameters of the biodynamics of the accumulation of Hg(II) and MeHg could reflect the species-dependent Hg concentrations in the bivalves. With the exception of black mussels, we found a significant relationship between the efflux rates of Hg(II) and the THg concentrations in the bivalves. The interspecific variations in the MeHg to THg ratio were largely controlled by the relative difference between the elimination rates of Hg(II) and MeHg. Stable isotope (δ 13 C) analysis indicated that the five bivalve species had contrasting feeding niches, which may also affect the Hg accumulation.

  • metallothionein like proteins turnover cd and zn biokinetics in the dietary cd exposed scallop Chlamys Nobilis
    Aquatic Toxicology, 2011
    Co-Authors: Fengjie Liu, Wenxiong Wang
    Abstract:

    Abstract In this study, we tested whether metallothionein-like proteins (MTLPs) affected the biokinetics of Cd and Zn in the scallops Chlamys Nobilis following dietary Cd exposure. The scallops were fed Cd-contaminated diatoms for 8 or 40 days, and then the tissue Cd concentrations, MTLP turnover and their standing stocks, Cd and Zn kinetics were monitored. After 8 days of dietary Cd exposure (at 98 or 196 μg Cd g−1), their Cd levels were increased by 7.4–12.5 times, newly synthesized MLTPs by 1.7–2.1 times, and their MLTP stocks doubled. However, after 40 days of dietary Cd exposure (at 58 or 115 μg Cd g−1), MTLP synthesis and MTLP stocks did not change despite the fact that Cd bioaccumulation increased by 2.7–4.2 times. MTLPs played little role in the overall Cd and Zn uptake from either food or water, since enhanced MTLP induction did not improve the sequestration of newly incoming Cd or Zn. As MTLP-metal complexes degraded, the released Cd was immediately sequestered by newly synthesized MTLPs while most Zn was depurated. This may explain why scallops eliminated Cd more slowly than Zn. Induced proteins were shown to play a minor role in the detoxification of dietary Cd in C. Nobilis, but the species can modify its Cd assimilation to reduce the impact of high dietary Cd levels. MTLPs are probably unsuitable as biomarkers for environmental monitoring involving C. Nobilis.

  • differential roles of metallothionein like proteins in cadmium uptake and elimination by the scallop Chlamys Nobilis
    Environmental Toxicology and Chemistry, 2011
    Co-Authors: Fengjie Liu, Wenxiong Wang
    Abstract:

    Metallothionein-like proteins (MTLPs) are important inducible ligands for Cd detoxification, but whether MTLPs are involved in Cd bioaccumulation remains unclear. The present study investigated the potential interrelationships between MTLP turnover and Cd biokinetics in the scallop Chlamys Nobilis with or without dissolved Cd pre-exposure. After Cd pre-exposure, increased synthesis rate and standing stock concentration of MTLPs as well as increased dissolved Cd uptake rate, were found in C. Nobilis. However, the level of newly sequestrated Cd by MTLPs in the pre-exposed scallops was similar to that of the controls, indicating that MTLPs had no effect on Cd uptake from the dissolved phase. Instead, Cd uptake rate was positively related to the Cd binding rate of cellular debris and organelles. In addition, no significant difference was observed in the Cd dietary assimilation efficiency of the scallops, showing that MTLPs played a minimal role in Cd uptake from the dietary phase. Conversely, the Cd efflux rate constant decreased by 68 to 75% in the pre-exposed scallops in comparison with that in the control. Correspondingly, progressive elevations of MTLP-bound Cd and standing stock MTLP concentration were observed in the pre-exposed individuals during the Cd elimination period. In the pre-exposed scallops, the faster de novo MTLP synthesis could remobilize and recycle more Cd from other intracellular pools, effectively reducing the Cd elimination rate. The present study thus showed the differential roles of MTLPs in Cd uptake and elimination in the bivalves. Environ. Toxicol. Chem. 2011; 30:738–746. © 2011 SETAC

  • inter individual variations in cadmium and zinc biodynamics in the scallop Chlamys Nobilis
    Marine Ecology Progress Series, 2009
    Co-Authors: Ke Pan, Wenxiong Wang
    Abstract:

    Intraspecific variability in the bioaccumulation of metals has been widely recorded in marine invertebrates, including marine bivalves. In the present study, we used biokinetic modelling and metal subcellular partitioning approaches to understand the intraspecific variability of metal bioaccumulation (Cd and Zn) in the scallop Chlamys Nobilis as a model organism. Significant individ- ual differences in metal body burdens were found in C. Nobilis. Cd concentrations varied by 3-fold and concentrations of Zn varied by 10-fold for individuals with similar body sizes. Contrasting metal biokinetics and metal subcellular partitioning were observed in different individuals. There was no significant relationship between the metal body burden and the dissolved metal uptake rate or the dietary assimilation efficiency in the individual scallops. However, a significant negative relationship was found between the metal efflux rate and the respective metal body burden, suggesting that efflux rate plays a key role in determining the intraspecific differences in the metal body burden in the tissues of scallops. Subcellular partitioning was closely related to the metal body burden in the scallops as well. A lower efflux rate or a higher proportion of metals stored in non-toxic form con- tributed to higher metal body burdens in individual scallops. Intrinsic variation may provide a popu- lation with more plasticity to counteract spatially or temporally abrupt environmental changes, and may be important for survival of microevolutionary events. Our results provide important information for interpreting the variability observed in natural environments.

  • biodynamics to explain the difference of copper body concentrations in five marine bivalve species
    Environmental Science & Technology, 2009
    Co-Authors: Ke Pan, Wenxiong Wang
    Abstract:

    Copper is an essential metal for organisms but can be toxic when high intake occurs. The interspecific and intraspecific differences in concentrations of Cu in the tissues of different bivalve species have been recognized but the underlying mechanisms leading to these differences remain speculative. In this study, the biokinetics of Cu, using 67Cu as a radioactive tracer, was investigated in five species of marine bivalves, including scallops Chlamys Nobilis, clams Ruditapes philippinarum, green mussels Perna viridis, black mussels Septifer virgatus, and oysters Saccostrea cucullata. All species have contrasting Cu concentrations in their bodies. Our results demonstrated the clear importance of biokinetics in controlling Cu concentrations in the bodies of bivalves. Assimilation efficiency (AE), feeding activity (filtration rate), and efflux rate all contributed to the observed interspecies differences. The AE and efflux rate were positively correlated with the respective Cu body burden, indicating their i...

Karsoon Tan - One of the best experts on this subject based on the ideXlab platform.

  • construction of genetic map and qtl analysis of carotenoid related trait based on est markers in noble scallop Chlamys Nobilis
    Aquaculture, 2021
    Co-Authors: Fang Meng, Karsoon Tan, Guofan Zhang, Huai Ping Zheng
    Abstract:

    Abstract Carotenoid is an important economic trait for genetic and breeding in animals and plants. The noble scallop Chlamys Nobilis is an important aquaculture bivalve in southern China. Studies in the noble scallop have shown that carotenoids content among individuals in their muscle are varies. In order to explain the variation, a genetic map was constructed in this study using F2 progenies with different carotenoids content, and then QTLs for carotenoids content in adductor and mantle were analyzed. Totally, 225 polymorphic markers (170 SNPs, 32 InDels and 23 SSRs) were developed from expressed sequence tags (ESTs). The female map had 16 linkage groups and spanned 595.2 cM with an average interval of 6.7 cM, and the male map had 19 linkage groups and spanned 745.7 cM with an average interval of 7.2 cM. However, the integrated map only contained 14 linkage groups, spanning 691.2 cM and with an average interval of 4.8 cM. A total of five QTLs were identified including three in the adductor and two in the mantle, which were distributed in linkage group 1 (Z1), 5 (Z5) and 12 (Z12), respectively. In addition, two QTLs on Z12 completely overlapped, which explained 28.0% in the adductor and 55.6% in the mantle of phenotypic variation, respectively, suggesting the presence of important carotenoid-determining genes in this region. The present study was the first to construct a genetic map using animals with different carotenoids content and identified five QTLs for carotenoids content, which can provide new insights for further understanding genetic mechanism of carotenoids deposition.

  • genome wide analysis of traf gene family and its response to bacterial infection in noble scallop Chlamys Nobilis with different carotenoids content
    Aquaculture, 2021
    Co-Authors: Hongkuan Zhang, Karsoon Tan, Huai Ping Zheng
    Abstract:

    Abstract Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are multifunctional adaptor proteins in the immune system, which play significant roles in the regulation of Toll-like receptor and RIG-I-like receptor signaling pathway in animals. Although many TRAF genes have been identified in mollusks, the systematic identification of the TRAF gene family in noble scallop Chlamys Nobilis has not been reported, and very little is known about its roles in scallop innate immunity. In this study, four TRAF genes (CnTRAF 2, CnTRAF3, CnTRAF4 and CnTRAF6) were identified and characterized from C. Nobilis. Sequence and phylogenetic analysis revealed that CnTRAFs contain typical conserved domains closely related to TRAFs of other mollusks. The motifs analysis of C. Nobilis CnTRAFs also showed that the conserved motifs were identical to other mollusks and vertebrates. The expression pattern of CnTRAF genes in tissues of brown and golden scallops (the carotenoid content of golden scallops is significantly higher than that of brown scallops) were not statistically significant, but in hemolymph of scallops challenged with bacteria, the expression of CnTRAF genes was significantly higher than that of control, suggesting that the CnTRAF genes play vital roles in the immunity of mollusks. Furthermore, at several time points after bacteria challenge, the expression level of CnTRAF genes in golden scallops were significantly higher than that of brown scallops, indicating that carotenoids may enhance CnTRAF genes expression and immunity. The systematic analysis of the roles of TRAFs in C. Nobilis provides valuable information for the further researches of CnTRAF genes.

  • carotenoids regulation in polymorphic noble scallops Chlamys Nobilis under different light cycle
    Aquaculture, 2021
    Co-Authors: Karsoon Tan, Hongkuan Zhang, Zhicheng Guo, Huai Ping Zheng
    Abstract:

    Abstract Light cycle is an important factor affecting the total carotenoid content (TCC) in tissues of noble scallops Chlamys Nobilis, but its regulatory mechanism is still unclear. In this study, adult polymorphic C. Nobilis (Nan'ao Golden Scallop and common brown scallop) were exposed to three different light cycles (24L/0D, 12L/12D and 0L/24D) for 10 days. The expression of carotenoid related genes (Scavenger Receptor class B (SRB) genes, β-carotene oxygenase (BCO) genes, and Retinoic acid receptors (RAR and RXR) genes) were determined by qRT-PCR. The results revealed that 24L/0D and 0L/24D treatments significantly increased the accumulation of TCC in adductor muscle of Nan'ao Golden Scallop and common brown scallop, respectively. The deposition of carotenoids in adductor muscle was induced by the up-regulation of SRB genes, of which was then up-regulation of BCO gene expression, followed by the up-regulation of RAR and/or RXR expression, and then further induced the expression of SRB and BCO genes. In hemolymph, the absorption mechanism of carotenoids may not involve SRB genes, or other carotenoid related genes may mask the role of SRB genes. The findings of this study provide important clues for further understanding the mechanism of TCC accumulation in polymorphic C. Nobilis under different light cycle.

  • potential causative factors of noble scallop Chlamys Nobilis mass mortality in nan ao island shantou china in 2017
    Science of The Total Environment, 2021
    Co-Authors: Karsoon Tan, Hongkuan Zhang, Huai Ping Zheng
    Abstract:

    Abstract Noble scallop Chlamys Nobilis is an important marine bivalve that has been extensively cultured in the south coast of China since the 1980s. Unfortunately, since the late 1990s, the farmed scallops often suffered from regional mass mortality, which results in enormous economic losses to farmers and industries. In 2017, another mass mortality event occurred in Nan'ao Island, Shantou, China. In this study, the cause of C. Nobilis mass mortality in 2017 was first investigated in the field, and then validated in a laboratory experiment. In the field, three sampling sites were selected according to the scallop mortality rate: Hunter Bay (90% mortality), Baisha Bay (67% mortality) and Longhai (6% mortality). Meanwhile, environmental parameters (temperature, salinity, DO, pH and chlorophyll a) of each site were also measured in situ. Then, water and scallop samples were collected randomly for the analysis of phytoplankton diversity and algal toxin activity using 18S rDNA and PP2A inhibition assay, respectively. In laboratory, healthy scallops were challenged with Karenia mikimotoi (1 × 103 cells/mL) for 30 h. The field results showed that no significant difference in those environmental parameters existed among the three sites, but the relative abundance of K. mikimotoi in seawater and scallops' intestines in Hunter Bay and Baisha Bay was significantly higher than that in Longhai, and sick scallops contained significantly higher algal toxin activity than healthy ones. Laboratory results revealed that challenged scallops with K. mikimotoi showed significantly higher mortality rate and algal toxin activity than healthy ones, and low density of K. mikimotoi (1 × 103 cells/mL) was sufficient to cause >50% scallops' mortality within 26 h. This study provides the first evidence that low K. mikimotoi cell density can cause massive mortality in C. Nobilis, and provides useful information as guide to prevent scallop mass mortality in the future.

  • a novel carotenoids producing marine bacterium from noble scallop Chlamys Nobilis and antioxidant activities of its carotenoid compositions
    Food Chemistry, 2020
    Co-Authors: Hongxing Liu, Karsoon Tan, Hongkuan Zhang, Dewei Cheng, Chuanxu Zhang, Xinxu Zhang, Huai Ping Zheng
    Abstract:

    Abstract Marine bacteria produce many bioactive compounds, including carotenoids. However, the quality of bacterium carotenoids is relatively unknown. Therefore, in this study, a novel carotenoids-producing bacterium Brevundimonas scallop Zheng & Liu was isolated from Chlamys Nobilis. The genome of the isolate was analyzed, carotenoid compounds were screened using HPLC-MS and the carotenoid production in B. scallop was monitored. The results revealed that the genome of B. scallop contained a carotenoid synthesis gene cluster, which involved in astaxanthin and hydroxy-astaxanthin biosynthesis. The 2,2′-dihydroxy-astaxanthin was the major carotenoid produced by B. scallop. The optimum culture condition for the highest carotenoids production (1303.62 ± 61.06 µg/g dry cells) for B. scallop was at temperature and salinity of 20 °C and 3% salt, respectively, in 10 g/L glucose as carbon source. The results showed the B. scallop is a new carotenoids resource in marine bivalve, which has an excellent antioxidative activity and potential industrial use.