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ABSTRACT: In this study, we investigated the gene expression profiling of disk abalone, Haliotis discus discus challenged by a mixture of three pathogenic bacteria Vibrio alginolyticus, Vibrio parahemolyticus, and Listeria monocytogenes using a cDNA microarray. Upon bacteria challenge, 68 (1.6%) and 112 (2.7%) gene transcripts changed their expression levels ≥2 or ≤2 -fold in gills and digestive tract, respectively. There were 46 tissue-specific transcripts that up-regulated specifically in the digestive tract. In contrast, only 13 transcripts showed gill-specific up-regulation. Quantitative real-time PCR was performed to verify microarray data and results revealed that candidate genes namely Krüppell-like factor (KLF), lachesin, muscle lim protein, thioredoxin-2 (TRx-2), nuclear factor interleukin 3 (NFIL-3) and abalone protein 38 were up-regulated. Also, our results further indicated that bacteria challenge may activate the transcription factors or their activators (Krüppell-like factor, inhibitor of NF-κB or Ik-B), inflammatory cytokines (IL-3 regulated protein, allograft inflammatory factor), other cytokines (IFN-44-like protein, SOCS-2), antioxidant enzymes (glutathione-S-transferase, thioredoxin-2 and thioredoxin peroxidase), and apoptosis-related proteins (TNF-α, archeron) in abalone. The identification of immune and stress response genes and their expression profiles in this microarray will permit detailed investigation of the stress and immune responses of abalone genes.
Fish & Shellfish Immunology 02/2011; 30(2):661-73. · 3.32 Impact Factor
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ABSTRACT: In Korea, the new permission criteria for industrial effluents based on Daphnia magna acute toxicity tests will be gradually implemented starting from 2011. Thus, in this study, toxicity assessment and identification using a marine species (Tigriopus japonicus) and the freshwater species (D. magna) was comparatively investigated. Effluent from an acid mine drainage treatment plant showed acute toxicity toward both organisms due to low pH, which was removed by neutralization of the effluent. Additionally, evaluation of the effluent of an electronics company revealed that Cu was attributable to the observed toxicity, and the effluent was more toxic toward T. japonicus than D. magna. Moreover, effluents from a metal plating factory were acutely toxic toward D. magna (6.50 TU), while they were not toxic against T. japonicus. Toxicity identification revealed that the high level of Cl- (12,841 mg L(-1)) was the cause of toxicity. Thus, the effluents had no effect on the marine species, T. japonicus. These findings suggest that a marine species rather than a freshwater species is more desirable for toxicity assessment of industrial effluent discharged into the saltwater, and thus should be considered in the legislation of toxicity-based discharge limits in Korea.
Marine pollution bulletin 12/2010; 63(5-12):370-5. · 2.63 Impact Factor
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ABSTRACT: Prolactin plays an essential role in ion uptake as well as reduction in ion and water permeability of osmoregulatory surfaces in euryhaline fish. Kryptolebias marmoratus is a euryhaline fish with unique internal self-fertilization. In order to understand the effect of different salinities and environmental endocrine-disrupting chemicals (EDCs) on the regulation of prolactin (PRL) and prolactin receptor (PRLR) genes, the full-length sequences of PRL and two PRLR genes were cloned from K. marmoratus. The expression pattern of K. marmoratus PRL (Km-PRL) and PRLR (Km-PRLR1, Km-PRLR2) mRNAs was analyzed in different developmental stages (2dpf to 5h post-hatching) and tissues of hermaphrodite fish. To investigate the effects of salinity changes and EDC exposure, the mRNA expression pattern of PRL, PRLR1 and PRLR2 was analyzed in exposed fish. The Km-PRL mRNA in the hermaphrodite was predominantly expressed in the brain/pituitary, the Km-PRLR1 mRNA was highly expressed in the intestine, while the Km-PRLR2 mRNA was intensively expressed in the gills. The expression of the Km-PRL mRNA generally increased from stage 1 (2 dpf) to stage 3 (12 dpf) in a developmental, stage-dependent manner. It decreased in stage 4 (12 dpf) and the hatching stage (stage 5). Km-PRLR1 and Km-PRLR2 mRNAs showed a gradual increase in expression from stage 1 (2 dpf) to stage 4 (12 dpf) and decreased by stage 5 (5 h post-hatching). Also, both mRNAs of PRLR showed a different expression pattern after exposure to different salinity concentrations (0, 33, and 50 ppt) in juvenile fish. The expression of PRL mRNA was upregulated at 0 ppt, but was downregulated at a moderately higher salinity concentration (33 to 50 ppt). The Km-PRLR1 mRNA showed upregulation at freshwater stress (0 ppt) compared to other concentrations of salinity (33 ppt to 50 ppt). The Km-PRLR2 mRNA was marginally upregulated at freshwater stress (0 ppt), but was downregulated at a higher salinity concentration (50 ppt) and showed no significant change in expression at 33 ppt salinity. Interestingly, both mRNAs showed upregulation in the brain (e.g. Km-PRL) and intestine (e.g. Km-PRLR1) after EDC exposure. These findings suggested that Km-PRL and two Km-PRLR mRNAs would be useful in analyzing the effect of different salinities as well as the modulatory effect of EDC exposure on these gene expressions in K. marmoratus.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 11/2010; 152(4):413-23. · 2.62 Impact Factor
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ABSTRACT: Pituitary gonadotropins (GTHs), follicle stimulating hormone beta (FSH-beta), and luteinizing hormone beta (LH-beta) are the key hormones in the hypothalamus-pituitary-gonad (HPG) axis, and form the heterodimers between a common alpha subunit (gonadotropin-alpha) and FSH-beta and/or LH-beta. To obtain a better understanding on the modulation of gonadotropin subunit genes expression upon bisphenol A (BPA) exposure in hermaphroditic fish, we studied differential regulation of gonadotropin subunit genes from Kryptolebias marmoratus after the exposure of several EDCs. Expression profiles of these three genes when using quantitative real-time RT-PCR revealed that brain/pituitary tissues were highly expressed in these genes compared to other tissues. At different developmental stages, expression of those genes dramatically increased over the course of development but showed a decrease in expression at the secondary male (showing atresia) stage. When adult fish were exposed to BPA (600 microg/L for 96 h), a significant upregulation of these three genes was observed in the brain/pituitary. A time course study also revealed the increased expression of gonadotropin subunit genes over 12 h with a more pronounced effect on the expression of FSH-beta and LH-beta genes, indicating that both genes were associated with the BPA exposure on the transcriptional regulation. This is the first report of gonadotropin subunit genes from K. marmoratus, with particular emphasis on the modulation of their expressions by EDCs. In addition, these findings suggest that EDCs modulate the expression of gonadotropin subunit genes and would act as potential biomarkers upon EDCs exposure.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 11/2010; 152(4):456-66. · 2.62 Impact Factor
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ABSTRACT: Cadmium (Cd) is a non-essential toxic heavy metal with the potential to induce oxidative stress. Cd toxicity and its capacity for accumulation in aquatic habitats have earned its recognition as a pollutant of immediate and widespread concern. To obtain a better understanding of oxidative stress-associated gene expression in different tissues, six antioxidant genes such as catalase (CAT), glutathione reductase (GR), glutathione peroxidase 1a (GPx1a), glutathione peroxidase 1b (GPx1b), Cu/Zn superoxide dismutase (Cu/Zn-SOD), and Mn superoxide dismutase (Mn-SOD) were cloned and fully sequenced in the river pufferfish, Takifugu obscurus. On tissue specific mRNA expression, the liver showed the highest expression when compared to other tissues, even though each antioxidant gene showed different modes of expression patterns in the examined tissues. Of the various antioxidant genes, GR was the most highly expressed in the liver, followed by CAT, GPx1, and Cu/Zn-SOD. For the time-course experiment, all the antioxidant genes were significantly induced over time except for Cu/Zn-SOD in the liver, and there was a 5-fold induction in hepatic GR, CAT, and Mn-SOD mRNA compared to the control. These findings indicate that the liver of T. obscurus has a robust antioxidant system. In addition, these results suggest that Cd exposure modulates the expression of antioxidant genes, and would indicate that the antioxidant genes would be a relevant biomarker of trace metal pollution such as Cd exposure in T. obscurus.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 11/2010; 152(4):473-9. · 2.62 Impact Factor
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ABSTRACT: Invertebrates play an increasing role in assessing the impacts of environmental contaminants in aquatic ecosystems. Substantial efforts were made to identify suitable and environmentally relevant models for toxicity testing. Rotifers have a number of promising characteristics which make them candidates worth considering in such efforts. They are small, simple in their organization, genetically homozygous, easy to cultivate. Rotifers are further widely distributed and ecologically important in freshwaters, in estuaries and coast, and also play an important role in the transportation of aquatic pollutants across the food web. In the last decades there has been a substantial increase of contributions on rotifers, particularly in areas of their ecology, geophylogeny, genomics and their behavioral, physiological, biochemical and molecular responses, following exposure to environmental chemicals and other stressors. Gene expression analysis enables ecotoxicologists to study molecular mechanisms of toxicity. Rotifers also appear as useful tools in the risk assessment of pharmaceuticals and their metabolites that find their way into aquatic ecosystems because their sensitivity to some of these substances is higher than that of cladocerans and algae. In respect to endocrine disruptors, rotifers seem to be particularly sensitive to androgenic and anti-androgenic substances, whereas copepods and cladocerans are typically more affected by estrogens and juvenile hormone-like compounds. Generally, a combination of whole-animal bioassays and gene expression studies allow an understanding of toxicological mechanisms. The purpose of this review is to demarcate the potential of using rotifers as important invertebrate aquatic model organisms for ecophysiology, ecotoxicology and environmental genomics. This review does not claim to find reasons for a superior use of rotifers in these fields. But the different phylogenetic allocation of rotifers in the Platyzoa (formerly Nemathelminthes) justifies its consideration since there are evolutionary differences in biochemical and genetic performances that need to be considered. Problems, controversials and needs for further studies are discussed. We are providing a literature survey here for the last 15 years that shows a steady increase of ecotoxicological research on rotifers.
Aquatic toxicology (Amsterdam, Netherlands) 10/2010; 101(1):1-12. · 3.12 Impact Factor
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ABSTRACT: O⁶-methylguanine-DNA methyltransferase (O⁶-MGMT; EC 2.1.1.63) is a key repair enzyme that helps to protect the cell against alkylation on DNA by removing a methyl group from the O⁶-position of guanine. Here, we cloned and sequenced the full-length O⁶-MGMT cDNA from the hermaphroditic fish, Kryptolebias marmoratus. Complete Km-O⁶-MGMT cDNA was 1324 bp in length, and the open reading frame of 567 bp encoded a polypeptide of 188 amino acid residues. Phylogenetic analysis revealed that Km-O⁶-MGMT was clustered with those of other fish species. Embryo, juveniles, and aged secondary fish had low levels of Km-O⁶-MGMT mRNA than adults, indicating more susceptibility to DNA damage by alkylating agent exposure during these developmental stages. Km-O⁶-MGMT mRNA levels differed according to tissue type and was highest in the liver. Exposure to an alkylating agent, N-methyl-N-nitrosourea (MNU) exposure increased the mRNA expression of tumor suppressor gene such as p53 and oncogenes such as R-ras1, R-ras3, N-ras, c-fos as well as Km-O⁶-MGMT mRNA in a time-dependent manner. On the contrary, several (anti)estrogenic compounds (17β-estradiol 100 ng/L, tamoxifen 10 μg/L, bisphenol A 600 μg/L, and 4-tert-octylphenol 300 μg/L) suppressed mRNA expression of Km-O⁶-MGMT in most tissues, especially the liver. In juvenile fish, 17β-estradiol, bisphenol A, and 4-tert-octylphenol also decreased the expression of Km-O⁶-MGMT mRNA in a time-dependent manner. Overall, our finding shows that Km-O⁶-MGMT mRNA levels can be modulated by environmental estrogenic compounds as well as alkylating agents. This finding will be helpful to improve our knowledge of the effects of estrogenic compounds that contain the genotoxic ability to inhibit the DNA repair process in aquatic animals.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 10/2010; 153(1):141-9. · 2.62 Impact Factor
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Chulhong Oh,
Mahanama De Zoysa,
Chamilani Nikapitiya,
Ilson Whang,
Yu Cheol Kim,
Do-Hyung Kang,
Soo-jin Heo,
Young-Ung Choi,
Cheol Young Choi, Jae-Seong Lee,
Jehee Lee
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ABSTRACT: We describe molecular characterization and transcriptional analysis of the gene encoding tumor suppressor QM-like protein, AbQM, in the disk abalone Haliotis discus discus. The full-length cDNA (765-bp) of AbQM was found to consist of a 654-bp ORF coding for a 218 amino acid protein of a 25 kDa molecular mass with a 10.2 isoelectric point. Analysis of AbQM sequence revealed the presence of characteristic motifs, including the ribosomal protein L10 signature, SH3-binding motif and two antibiotic binding sites. Phylogenetic analysis confirmed that AbQM is closely related to other mollusk QM proteins, and altogether they form a mollusk QM protein sub-family which displays evolutionary conservation from yeast to human. Tissue-specific expression and transcriptional regulation of AbQM was analyzed by quantitative real-time PCR in response to bacterial (Vibrio alginolyticus and Vibrio parahemolyticus, Listeria monocytogenes) and viral (viral hemorrhagic septicemia virus, VHSV) challenge. AbQM transcripts were found to be expressed ubiquitously in all examined tissues in a constitutive manner, as similar expression levels were detected in hemocytes, mantle, digestive tract and muscle. Upon bacterial and VHSV challenge, AbQM showed significant up-regulation in gills, but not in hemocytes. Taken together, these findings suggest that AbQM in abalone-like mollusks can respond to and facilitate a defensive effect against pathogenic infection.
Fish & Shellfish Immunology 09/2010; 29(3):494-500. · 3.32 Impact Factor
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ABSTRACT: To demonstrate the effectiveness of microarrays for the detection of jellyfish, we developed a low density DNA chip based on the mitochondrial COI gene sequences of scyphozoans (jellyfish). We designed species-specific oligonucleotide probes by sequence comparisons between scyphozoans and other cnidarians such as hydrozoans and anthozoans. Each amine-labelled capture probe was arrayed onto a silylated slide. PCR products of the COI gene were hybridized to the DNA microarray that contained COI consensus sequences. We tested the ability of the DNA chip to discriminate between species from the genera Aurelia and Chrysaora based on samples of both species from the polyp and ephyra stages. The array produced unique hybridization patterns for each of the two tested jellyfish species. Furthermore, we were able to simultaneously detect individual jellyfish species from mixtures of these two different species in the laboratory and from environmental samples. These results show that the low density DNA chip that we designed can be used as a technical platform for parallel molecular detection of various jellyfish species.
Journal of the Marine Biological Association of the UK 08/2010; 90(06):1111 - 1117. · 1.00 Impact Factor
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ABSTRACT: The complete amino acid sequence of a calcium-regulatory gene (denoted as Ab-CaReg I) was identified from the disk abalone Haliotis discus discus cDNA library. The Ab-CaReg I is composed of 176 amino acids and the calculated molecular mass and isoelectric point were 20 and 4.2, respectively. The sequence homology of Ab-CaReg I was 28-30 and 18-27% of known calmodulin and troponin C, respectively. Four characteristic calcium-binding EF hand motifs with some modifications at conserved positions of known homologous calmodulin genes were observed in the sequence. The tissue-specific transcription analysis and variation of mRNA transcription level of Ab-CaReg I in gills and mantle after animals were immersed in seawater containing 2000 ppm CaCl(2) was quantified by SYBR Green real-time PCR analysis. Transcription variation of Ab-CaReg I in hemocytes and gills followed by bacteria challenge (Vibrio alginolyticus, Vibrio parahaemolyticus and Listeria monocytogenes) was used to investigate Ab-CaReg I in immune responses. Transcripts of Ab-CaReg I mRNA were mainly detected in hemocytes, mantle, muscle, gills, digestive tract and hepatopancreas with highest expression in hemocytes. The CaCl(2) immersion significantly altered the Ab-CaReg I mRNA transcription level by 3 h, compared to animals in normal seawater (control). The mRNA expression of Ab-CaReg I in gills and hemocytes was upregulated significantly to 11-fold and 4-fold in 3 h compared to control (uninfected), respectively, in bacteria-challenged abalones. The results suggest that Ab-CaReg I could be effectively induced to maintain internal Ca(2+) homeostasis of the animal due to influx of Ca(2+) in the cells by external stimuli such as a high dose of Ca(2+) and pathogens like bacteria.
Fish & Shellfish Immunology 08/2010; 29(2):334-42. · 3.32 Impact Factor
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ABSTRACT: To analyze the mitogenome of the amphipod Onisimus nanseni, we amplified the complete mitogenome of O. nanseni using long-PCR and genome walking techniques. The mitogenome of O. nanseni is circular and contains all the typical mt genes (2 rRNAs, 22 tRNAs, and 13 protein-coding genes). It has two peculiar non-coding regions of 148bp and 194bp. The latter can be involved in replication and termination processes. The total length of the pooled protein-coding, rRNA, and tRNA genes is shorter than those of other crustaceans. In addition, the intergenic spacers of the O. nanseni mitogenome are considerably shorter in length than those of other crustaceans. Fourteen adjacent genes overlap, resulting in a compact mitogenomic structure. In the O. nanseni mitogenome, the AT composition is elevated, particularly in the control regions (78.9% AT), as has been demonstrated for two other amphipods. The tRNA order is highly rearranged compared to other arthropod mitogenomes, but the order of protein-coding genes and rRNAs is largely conserved. The gene cluster between the CO1 and CO3 genes is completely conserved among all amphipods compared. This provides insights into the evolution and gene structures of crustacean mitochondrial genomes, particularly in amphipods.
Comparative Biochemistry and Physiology Part D Genomics and Proteomics 06/2010; 5(2):105-15. · 1.72 Impact Factor
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ABSTRACT: Here, we report the identification and characterization of allograft inflammatory factor-1 (AIF-1) from disk abalone Haliotis discus discus that was denoted as AbAIF-1. The full-length cDNA of AbAIF-1 consists of a coding region (453 bp) for 151 amino acids with a 17 kDa molecular mass. Analysis of AbAIF-1 sequence showed that it shares characteristic two EF hand Ca(+2)-binding motifs. Results from phylogenetic analysis further confirm that AbAIF-1 is a member of the AIF-1 family similar to invertebrate and vertebrate counterparts suggesting it has high evolutional conservation. Tissue-specific expression and transcriptional regulation of AbAIF-1 were analyzed after bacteria (Vibrio alginolyticus, Vibrio parahemolyticus and Lysteria monocytogenes), viral hemorrhagic septicemia virus (VHSV) immune challenge and during tissue injury by quantitative real-time PCR. It is shown that the expression of AbAIF-1 mRNA was expressed ubiquitously in all selected tissues in constitutive manner showing the highest level in hemocytes. Upon bacteria and VHSV challenge, AbAIF-1 showed the significant up-regulation in hemocytes than gills. After the tissue injury in shell and mantle, AbAIF-1 and antioxidant selenium-dependant glutathione peroxidase (SeGPx) transcripts were significantly upregulated in abalone hemocytes. Taken together, these findings suggest that AIF-1 could response against the pathogenic challenge or tissue injury in abalone like mollusks. Also, AbAIF-1 may involve in wound healing and shell repair after the tissue injury of abalone.
Fish & Shellfish Immunology 05/2010; 29(2):319-26. · 3.32 Impact Factor
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ABSTRACT: This review summarizes current knowledge on ultraviolet radiation (UVR)-induced cellular and molecular damage in marine ectotherms (invertebrates and fish). UVR impairs sperm motility, reduces fertilization, and causes embryo malformation that in turn affects recruitment and therefore the sustainability of natural populations. The direct molecular effects of UVR are mediated by absorption of certain wavelengths by specific macromolecules and the dissipation of the absorbed energy via photochemical reactions. Most organisms have defense mechanisms that either prevent UVR-induced damage, or mechanisms that repair the damage. Photoprotective pigments, antioxidant defense compounds, and cell cycle development genes are some of the molecules involved in UVR defense. Photoenzymatic repair and nucleotide excision repair are the two primary DNA repair systems in marine ectotherms. We anticipate that toxicogenomic studies will gain importance in UVR research because they can elucidate the primary processes involved in UVR damage and the cellular response to this damage.
Aquatic toxicology (Amsterdam, Netherlands) 04/2010; 97(1):3-14. · 3.12 Impact Factor
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ABSTRACT: To assess the effects of endocrine-disrupting chemicals on the expression and activity of aromatase in the gonads of Bombina orientalis, a common amphibian, we intraperitoneally injected nonylphenol or bisphenol-A and then examined aromatase mRNA levels by RT-PCR as well as aromatase enzymatic activity by tritiated water release assays. To design primers for the RT-PCR, we cloned the B. orientalis aromatase gene using RT-PCR and degenerate primers. The full-length cDNA was obtained by 5'- and 3'-RACE PCR. The complete sequence of the B. orientalis aromatase gene revealed an open reading frame of 1500 bp encoding a deduced protein of 500 amino acids. Semi-quantitative RT-PCR indicated that nonylphenol or bisphenol-A injection did not significantly affect the expression of B. orientalis aromatase mRNA. However, a 48-hr treatment with nonyphenol or bisphenol A reduced aromatase activity to 47% and 32% of the control, respectively. These results suggest that endocrine disrupters can effectively modulate the activity of B. orientalis aromatase without affecting its mRNA levels.
ZOOLOGICAL SCIENCE 04/2010; 27(4):338-43. · 0.95 Impact Factor
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ABSTRACT: Induction of vitellogenin (Vg) has been used as a biomarker of exposure to heavy metals and endocrine-disruption chemicals (EDCs) in aquatic organisms. Here, we identified the full-length Vg1 and Vg2 sequence from the brackish water copepod, Paracyclopina nana. Vg1 gene contained 5718bp of the open reading frame (ORF) that encoded the putative protein of 1905 amino acids residues, while Vg2 gene consisted of 5442bp of ORF, encoding the putative protein of 1813 amino acids residues. P. nana Vgs showed highly conserved domains in the N-terminal region. The phylogenetic analysis revealed that P. nana Vgs are distinct from other arthropods, such as insects and decapods, as it formed a clade with other copepods, Tigriopus japonicus and salmon louse (Lepeophtheirus salmonis). The expression of Vg transcripts was detectable after the copepodid stages 4-5. Female copepods expressed over 83 times and 223 times more Vg1 and Vg2 transcripts, respectively, than males. When copepods were exposed to heavy metals (0.1mg/L Cd, 0.4mg/L Cu, and 2mg/L AsIII) for 24, 48, 72, and 96h, P. nana Vg transcripts were highly induced in a time-dependent manner. Interestingly, Vg2 gene was more susceptible than Vg1 to trace heavy metal exposure. This finding indicates that P. nana Vgs provide a potential indicator for assessing the toxic effect of heavy metals. In addition, we suggest P. nana as a potential model species for risk-assessment to environmental pollutants in brackish water.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 04/2010; 151(3):360-8. · 2.62 Impact Factor
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ABSTRACT: A novel antistasin-like cDNA homologue named as Ab-Antistasin was isolated from the disk abalone Haliotis discus discus normalized cDNA library. The Ab-Antistasin (1398-bp) consisted of an 1185-bp open reading frame encoding 395 amino acid (aa) residues. The predicted molecular mass and isoelectric point of Ab-Antistasin was 44 kDa and 8.5, respectively, and showed highest identity (23.1%) to Hydra magnipapillata antistasin. The most striking feature of Ab-Antistasin is the 12-fold internal repeats (IR) of an antistasin-like domain. Ten of the 12 IR domains (26-27 aa) are highly conserved, with 6 cysteines and 1 glycine. Ab-Antistasin was comprised of three Bowman-Birk serine protease inhibitor family motifs. The recombinant Ab-Antistasin (rAb-Antistasin) was over-expressed in Escherichia coli and purified using a pMAL system. rAb-Antistasin (10 microM) was able to inhibit trypsin activity by 66% in a dose-dependent manner. Moreover, it exhibited low prolongation activity for coagulation in an APTT assay (86.0 s compared to control 42.0 s) with human blood. Endogenous Ab-Antistasin mRNA was found to be expressed in digestive tract, hepatopancreas, hemocytes, abductor muscle and mantle, with highest expression levels in digestive tract followed by hepatopancreas and hemocytes. Quantitative real time PCR results revealed that Ab-Antistasin transcription was significantly induced at 3 h post-infection (p.i.) after challenged by a mixture of bacteria (Vibrio alginolyticus, Vibrio parahemolyticus, and Listeria monocytogenes) in the abalone digestive tract; in the hemocytes, induction occurred at 6 and 12 h. The results indicated that Ab-Antistasin could play an important role in the immune responses of mollusks.
Fish & Shellfish Immunology 04/2010; 28(4):661-71. · 3.32 Impact Factor
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ABSTRACT: The lipopolysaccharide-induced TNF-alpha factor (LITAF) and Rel family nuclear factor kappaB (Rel/NF-kB) are two important transcription factors which play major roles in the regulating inflammatory cytokine, apoptosis and immune related genes. Here, we report the discovery of disk abalone LITAF (AbLITAF) and Rel/NF-kB (AbRel/NF-kB) homologues and their immune responses. Full-length cDNA of AbLITAF consists of 441 bp open reading frame (ORF) that translates into putative peptide of 147 aa. Analysis of AbLITAF sequence showed it has characteristic LITAF (Zn(+2)) binding domain with two CXXC motifs. Phylogenetic analysis results further revealed that AbLITAF is a member of LITAF family. AbRel/NF-kB is 584 aa protein that contains several characteristic motifs including Rel homology domain (RHD), Rel protein signature, DNA binding motif, nuclear localization signal (NLS) and transcription factor immunoglobulin - like fold (TIG) similar to their invertebrate and vertebrate counterparts. Tissue specific analysis results showed that both AbLITAF and AbRel/NF-kB mRNA was expressed ubiquitously in all selected tissues in constitutive manner. However, constitutive expression of AbLITAF was higher than AbRel/NF-kB in all tissues except mantle. Upon immune challenge by bacteria (Vibrio alginolyticus, Vibrio parahemolyticus and Lysteria monocytogenes) and viral hemoragic septicemia virus (VHSV), AbLITAF showed the significant up-regulation in gills while AbRel/NF-kB transcription was not change significantly. Based on transcriptional response against immune challenge, we could suggest that regulation of TNF-alpha expression may have occurred mainly by LITAF activation rather than NF-kB in disk abalone. The cumulative data from other molluscs and our data with reference to TNF-alpha, LITAF and Rel/NF-kB from disk abalone provide strong evidence that LITAF and NF-kB are independent pathways likely to occur throughout the Phylum mollusca.
Fish & Shellfish Immunology 02/2010; 28(5-6):754-63. · 3.32 Impact Factor
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ABSTRACT: The copepod, Tigriopus japonicus has been recognized as an excellent marine model species for ecotoxicological studies. The present study cloned and characterized the p53 gene of this copepod and studied its expression pattern. We discovered that p53 expression patterns varied among different developmental stages of the copepod, having the highest expression in the adult. Such variation was possibly associated with the molting cycle. By using real-time RT-PCR, we further investigated the modulatory pattern of the p53 gene in the copepod after exposure to three alkylphenols (i.e. nonylphenol, octylphenol, and bisphenol A) which are known as endocrine disruption chemicals (EDCs). The results showed that the three alkylphenols significantly induced p53 gene expression in the copepod, indicating the involvement of p53 in such stress-responses. Thus, the copepod p53 gene provides one of the stress-response biomarkers for exposure to EDC-like compounds.
Marine environmental research 01/2010; 69 Suppl:S77-80. · 1.76 Impact Factor
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ABSTRACT: The intertidal copepod, Tigriopus japonicus, has been recognized as a promising model species for marine environmental genomics. To obtain extensive genomic DNA sequences from this species, we sequenced genomic DNA from adult copepods using genomic sequencers GS-FLX and GS-FLX-Titanium and attained 1,914,995 reads (average read length 299.8 bp) including 574.2 Mb of genomic DNA information. After subjecting them to assembly, we acquired 193,642 contigs (total contigs length 129.7 Mb), and finally were able to obtain 10,894 unigenes (E-value>0.1; length>200 bp) containing 33,081,455 bp after a nonredundant (NR) blast search. In this paper, we summarize the genomic DNA sequences of T. japonicus and discuss its potential use in environmental genomics and ecotoxicological studies for uncovering mechanisms of environmental stresses and chemical toxicities to marine crustaceans.
Marine environmental research 01/2010; 69 Suppl:S21-3. · 1.76 Impact Factor
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ABSTRACT: Ecdysteroids are steroid hormones that play an important role in development, growth, molting of larva, and reproduction in the Arthropoda. The effect of ecdysteroids is mediated by its binding to ecdysteroid receptor (EcR). To investigate the role of EcR during development and the effect to environmental stressors on EcR expression in a copepod, we isolated and characterized cDNA and 5'-promoter region of the Tigriopus japonicus EcR (TJ-EcR), and studied mRNA expression pattern. The full-length TJ-EcR cDNA sequence was 1962bp in length and the open reading frame encoded 546 amino acids. The deduced TJ-EcR protein contained well-conserved DNA-binding domain and ligand-binding domain. Phylogenetic analysis revealed that TJ-EcR was clustered with the EcR of other crustaceans. TJ-EcR mRNA was expressed in a developmental stage-specific manner: high in early developmental stages and low in the adult stage. Significantly elevated expression of the TJ-EcR gene in adults was detected at hypersalinity (42ppt) and high temperature (35 degrees C) condition. The 5'-flanking region of TJ-EcR gene contains heat shock protein 70 response elements, implying that the environmental stressors may affect its expression via the stress-sensor. In addition, bisphenol A (100microg/L) repressed TJ-EcR expression. Our results suggest that TJ-EcR could be a biomarker for the monitoring of the impact of environmental stressors in copepods.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 12/2009; 151(3):303-12. · 2.62 Impact Factor
