Publications by authors named "Guizhong Wang"

27 Publications

  • Page 1 of 1

B-type allatostatin regulates immune response of hemocytes in mud crab Scylla paramamosain.

Dev Comp Immunol 2021 Jul 22;120:104050. Epub 2021 Feb 22.

College of Fisheries, Jimei University, Xiamen, 361021, China. Electronic address:

B-type allatostatins (AST-B) are neuropeptides that have important physiological roles in arthropods, they have also been identified in a number of crustacean species. Recent research on neuroendocrine-immune (NEI) regulatory system in invertebrates has exploded, it reveals that the NEI network plays an indispensable role in optimizing the immune response and maintaining homeostasis. Herein, mud crab Scylla paramamosain provides a primitive and ancient model to study crosstalk between the neuroendocrine and immune systems. In this study, qRT-PCR analysis showed that the nervous system was the main production site for Sp-AST-B mRNA in S. paramamosain, while its receptor gene (Sp-AST-BR) mRNA could be detected in all the analyzed tissues including hemocytes. This reveals that AST-B might act as a pleiotropic neuropeptide. In situ hybridization further confirmed that granular cells of hemocyte subpopulations express Sp-AST-BR. Time-course analysis revealed that bacteria-analog LPS or virus-analog Poly (I:C) challenge significantly induced Sp-AST-B expression in the thoracic ganglion, and the expression of Sp-AST-BR in hemocytes were also positively changed. Furthermore, mud crabs treated with a synthetic AST-B peptide significantly increased the mRNA levels of AST-BR, nuclear factor-κB (NF-κB) transcription factor (Dorsal and Relish), pro-inflammatory cytokine (IL-16) and immune-effector molecules, and also dramatically enhanced the nitric oxide (NO) production and phagocytic activity in hemocytes. Meanwhile dsRNA-mediated knockdown of Sp-AST-B remarkably suppressed the NO concentrations, phagocytic activity and the expression of immune related genes, resulting in markedly impaired ability of crabs to inhibit bacterial proliferation in vivo. Combined, these data demonstrate that AST-B induced innate immune in the mud crab.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dci.2021.104050DOI Listing
July 2021

Hepatopancreas immune response during molt cycle in the mud crab, Scylla paramamosain.

Sci Rep 2020 08 4;10(1):13102. Epub 2020 Aug 4.

College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.

Molt is a critical developmental process in crustaceans. Recent studies have shown that the hepatopancreas is an important source of innate immune molecules, yet hepatopancreatic patterns of gene expression during the molt cycle which may underlie changes in immune mechanism are unknown. In this study, we performed Illumina sequencing for the hepatopancreas of the mud crab, Scylla paramamosain during molt cycle (pre-molt stage, post-molt stage, and inter-molt stage). A total of 44.55 Gb high-quality reads were obtained from the normalized cDNA of hepatopancreas. A total of 70,591 transcripts were assembled; 55,167 unigenes were identified. Transcriptomic comparison revealed 948 differentially expressed genes (DEGs) in the hepatopancreas from the three molt stages. We found that genes associated with immune response patterns changed in expression during the molt cycle. Antimicrobial peptide genes, inflammatory response genes, Toll signaling pathway factors, the phenoloxidase system, antioxidant enzymes, metal-binding proteins and other immune related genes are significantly up-regulated at the post-molt stage and inter-molt stage compared with the pre-molt stage, respectively. These genes are either not expressed or are expressed at low levels at the pre-molt stage. To our knowledge, this is the first systematic transcriptome analysis of genes capable of mobilizing a hepatopancreas immune response during the molt cycle in crustaceans, and this study will contribute to a better understanding of the hepatopancreas immune system and mud crab prophylactic immune mechanisms at the post-molt stage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-70139-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403367PMC
August 2020

Transcriptional Inhibition of by Crustacean Female Sex Hormone in the Mud Crab, .

Int J Mol Sci 2020 Jul 26;21(15). Epub 2020 Jul 26.

College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.

In crustaceans, the regulation of sex differentiation is mediated by insulin-like androgenic hormone (IAG) and crustacean female sex hormone (CFSH). CFSH is reported to inhibit IAG gene () expression in the mud crab , but the regulatory mechanism is not well understood. A 2674 bp 5' flanking contains many potential transcription factor binding sites. In this study, analysis of serially deleted 5' flanking and site-directed mutation (SDM) of transcription factor binding sites of the same gene showed that the promoter activity of reporter vectors with Sox-5-binding site, signal transducers and activators of transcription (STAT)-binding site and activator protein 1 (AP-1)-binding site were significantly higher than that of vectors without these regions, suggesting that they were involved in transcriptional regulation of expression. The expression analysis of these transcription factor showed that there was no difference in the level of mRNA in and in androgenic gland treated with recombinant CFSH, but expression of was significantly reduced, suggesting that CFSH regulates the expression of , inhibiting its function to regulate . Further experiment revealed that RNAi mediated gene knockdown reduced the expression of . These results suggested that CFSH regulates by inhibiting STAT. This is a pioneering finding on the transcriptional mechanism of gene in crustaceans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21155300DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7432471PMC
July 2020

DNA Methylation Inhibits the Expression of CFSH in Mud Crab.

Front Endocrinol (Lausanne) 2020 9;11:163. Epub 2020 Apr 9.

College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.

Crustacean female sex hormone (CFSH) is a key regulator of crustacean sex differentiation. The expression of in the mud crab showed a tissue-specific and gender-variant pattern. To explore the role of DNA methylation in expression, the 5'-flanking region of was cloned, and one CpG island containing 12 CpG sites was found. Results of sodium bisulfite sequencing and methylated DNA immunoprecipitation showed that CpG island methylation was stable in the eyestalk ganglion during ovarian development of the females, which was significantly lower than that in the muscle of the females and in the eyestalk ganglion of the males. Such results suggested that the involvement of DNA methylation in regulating expression followed an eyestalk ganglion-specific and gender-variant pattern. The analysis of CpG dinucleotide site methylation and activity of the site-directed mutation (SDM) reporter vector further demonstrated that methylation inhibited expression by blocking the binding of transcription factor Sp1. The finding suggested for the first time the involvement of CpG methylation in the regulation of expression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fendo.2020.00163DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160318PMC
March 2021

C-Type allatostatin and its putative receptor from the mud crab serve an inhibitory role in ovarian development.

J Exp Biol 2019 11 6;222(Pt 21). Epub 2019 Nov 6.

College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China

C-Type allatostatins are a family of peptides that characterized by a conserved unblocked PISCF motif at the C-terminus. In insects, it is well known that C-type allatostatin has a potent inhibitory effect on juvenile hormone biosynthesis by the corpora allata. C-Type allatostatin has been widely identified from crustacean species but little is known about its roles. Therefore, this study investigated the tissue distribution patterns of C-type allatostatin and its putative receptor in the mud crab , and further explored its potential effect on vitellogenesis. Firstly, cDNAs encoding C-type allatostatin () precursor and its putative receptor () were isolated. Subsequently, RT-PCR revealed that was mainly expressed in the nervous tissue, middle gut and heart, whereas had extensive expression in all tissues tested except the eyestalk ganglion and hepatopancreas. In addition, hybridization in the cerebral ganglion showed that was localized in clusters 6 and 8 of the protocerebrum, clusters 9, 10 and 11 of the deutocerebrum, and clusters 14 and 15 of the tritocerebrum. Whole-mount immunofluorescence revealed a similar distribution pattern. Synthetic AST-C had no effect on the abundance of vitellogenin () in the hepatopancreas and ovary but significantly reduced the expression of its receptor () in the ovary in a dose-dependent manner Furthermore, expression, vitellin content and oocyte diameter in the ovary were reduced 16 days after the first injection of -AST-C. Finally, hybridization showed that transcript was specifically localized in the oocytes, which further indicated that the oocytes are the target cells for AST-C. In conclusion, our results suggested that the AST-C signaling system is involved in the regulation of ovarian development, possibly by directly inhibiting the uptake of yolk by oocytes and obstructing oocyte growth.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1242/jeb.207985DOI Listing
November 2019

Reliability assessment of an optical current sensor based on accelerated aging tests.

Appl Opt 2019 Jun;58(18):5107-5114

The operational reliability directly affects the practical application of optical current transformers (OCTs) in smart substations. As the key component of the OCT, the reliability of the optical current sensor (OCS) largely determines the reliability level of the OCT. This paper proposes a reliability assessment method of the OCS based on accelerated aging tests. The failure modes and failure mechanisms of the OCS are analyzed, and the concept of OCS insertion loss variation is proposed. An allowable range of insertion loss variation is selected as the failure criterion of the OCS. From the viewpoint of the OCS measurement error generated by the quantization error of the analog-to-digital converter, the allowable range of insertion loss variation is obtained. By selecting a high temperature as the accelerated thermal stress, we design the accelerated aging test scheme of the OCS and analyze the sample test data to obtain the activation energy of the OCS insertion loss failure. Based on this activation energy, the median time to failure and instantaneous failure rate curve of the OCS at normal temperature are obtained. The results indicate that the designed OCS has an expected service life of 50 years and a low instantaneous failure rate at normal temperature. This paper provides basic critical reliability analysis data for the system reliability assessment of OCTs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/AO.58.005107DOI Listing
June 2019

Jones matrix physical parameters for media in inhomogeneous fields.

Appl Opt 2018 Aug;57(22):6283-6289

Inhomogeneous media are affected by a physical or an electromagnetic field, where the off-diagonal elements of the Jones matrix are complex numbers with both real and imaginary parts. Inhomogeneities of the electromagnetic field result in the eigenvalue coordinate system changing along the light path. In this study, we used the unitary transformation to propose a Jones matrix of the inhomogeneous-field-induced medium with three physical or electromagnetic parameters: the medium's phase delay, induction angle, and inhomogeneous angle. This Jones matrix and the integral formulas of its three parameters are applicable to not only remarkable optical effects but also for the light propagation process of inhomogeneous-field-induced media.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/AO.57.006283DOI Listing
August 2018

Crustacean Female Sex Hormone From the Mud Crab Is Highly Expressed in Prepubertal Males and Inhibits the Development of Androgenic Gland.

Front Physiol 2018 17;9:924. Epub 2018 Jul 17.

College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.

Recently, the crustacean female sex hormone (CFSH), which is considered a female-specific hormone, has been shown to play a crucial role in female phenotypes in crustaceans. In this study, two transcripts ( and ) encoding the same CFSH precursor were cloned from the mud crab . Homology and phylogenetic analysis showed that CFSHs were homologous to interleukin-17 and highly conserved among brachyuran crabs. PCR analysis revealed that was expressed exclusively in the eyestalk ganglion of both prepubertal males and females, and surprisingly, the abundance of transcripts detected in the males were not significantly different from that of the females ( > 0.05). In addition, mRNA hybridization showed that was localized in the X-organ of the male eyestalk ganglion. During the development of the androgenic gland (AG), the level of mRNA in AG remained at low levels from stages I to II (early stage) but had a significant increase at stage III (mature stage). In contrast, the level of transcripts in the eyestalk ganglion was high in the early stage but extremely low in the mature stage. To investigate the potential function of CFSH in male , the recombinant protein (∼20 kDa) was expressed in and was subsequently added to AG explants . It was demonstrated that recombinant protein significantly reduced the expression of in the AG explants at a concentration of 10 M ( 0.05). In conclusion, our study provides the first piece of evidence that shows CFSH from the eyestalk ganglion acts as a negative regulator inhibiting the development of AG in crustaceans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphys.2018.00924DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6056722PMC
July 2018

Comparative study on the effects of two diatoms as diets on planktonic calanoid and benthic harpacticoid copepods.

J Exp Zool A Ecol Integr Physiol 2018 Jul 24. Epub 2018 Jul 24.

College of Ocean and Earth Science, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.

Two diatoms, Chaetoceros muelleri and Nitzschia closterium f. minutissima, were used for rearing nauplii to adults of Tigriopus japonicus, Acartia pacifica, and Pseudodiaptomus annandalei at different concentrations. The survival rates to adults and activities of superoxide dismutase (SOD) and glutathione-S-transferase (GST) of the adult copepods were measured. The results showed that when fed on N. closterium f. minutissima, A. pacifica was unable to complete naupliar development; while SOD and GST activities of P. annandalei fed N. closterium f. minutissima were significantly higher than those fed the control algae Isochrysis galbana (Prymnesiod), suggesting this diatom species is harmful to these calanoid copepods. The survival rates of T. japonicus were very high when fed N. closterium f. minutissima, indicating that T. japonicus has high acceptance to diatoms. To evaluate whether calanoid copepod had the capacity to acclimatize to diatoms, P. annandalei was cultured for four generations on the two diatoms at 1.7 μgC/ml and survival rates as well as SOD and GST activities were determined for each generation. It was shown that starting at the second generation, P. annandalei exhibited adaption to the diatoms with improved survival. When fed on N. closterium f. minutissima, both SOD and GST activities of P. annandalei showed a trend of decreasing with the progress of generation, whereas no significant difference was found among four generations on C. muelleri. This study demonstrates that whether a diatom species is considered harmful to copepods, which is largely species specific, and diatom concentration is an important influencing factor. Additionally, the capacity of copepod adaption to diatoms over time should not be neglected.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jez.2215DOI Listing
July 2018

Characterization of CCTα and evaluating its expression in the mud crab Scylla paramamosain when challenged by low temperatures alone and in combination with high and low salinity.

Cell Stress Chaperones 2015 Sep 30;20(5):853-64. Epub 2015 Jun 30.

College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China.

Chaperonin containing the T-complex polypeptide-1 (CCT), which is known to be involved in intracellular assembly and folding of proteins, is a class of chaperonin omnipresent in all forms of life. Previous studies showed that CCT played a vital role in cold hardiness of various animals. In order to understand the response of the polypeptide complex to low temperature challenge and other environmental stresses, a subunit of CCT (CCTα) was cloned from the mud crab Scylla paramamosain by expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE). The full-length cDNA SpCCTα was of 1972 bp and contained a 1668 bp open reading frame (ORF) encoding a polypeptide of 555 amino acids with four conserved motifs. The messenger ribonucleic acid (mRNA) levels of SpCCTα in ten tissues of adult S. paramamosain was subsequently examined and the highest expression was found in muscle, followed by gill, hepatopancreas, thoracic ganglion, hemocyte, heart, cerebral ganglion, stomach, eyestalk ganglion, and epidermis. The expressions of SpCCTα in the muscle of sub-adult crabs (pre-acclimated to 28 °C) subjected to the challenges of both lower temperatures (25, 20, 15, and 10 °C) alone and low temperatures (15 and 10 °C) in combination with salinity of 35 and 10 were further investigated by fluorescent quantitative real-time PCR (qPCR). It was revealed that when exposed to lower temperatures alone, the mRNA transcripts of the SpCCTα gene in the muscle were generally induced for significant higher expression at 10 °C treatment than the 25, 20, and 15 °C treatments; meanwhile, exposure to 15 °C also frequently led to significantly higher expression than those at 20 and 25 °C. This finding indicated that the up-regulation of SpCCTα was closely related to the cold hardiness of S. paramamosain. The results of an additional experiment challenging the sub-adult crabs with various combinations of low temperatures with different salinity conditions generally demonstrated that at both 10 and 15 °C, the expression of SpCCTα under the high salinity of 35 was significantly lower than that at low salinity of 10, implying that the damages caused by low temperatures with high salinity were less than that under low salinity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12192-015-0612-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4529868PMC
September 2015

500 MHz spaced Yb:fiber laser frequency comb without amplifiers.

Opt Lett 2014 May;39(9):2534-6

An optical frequency comb based on Yb:ring fiber laser was demonstrated. This is the first time, to our knowledge, f(ceo) has been generated directly from the oscillator without further amplifications above 500 MHz repetition rate. The signal-to-noise ratio of the offset frequency was above 40 dB at 300 kHz resolution bandwidth, which supports easy stabilization. The offset frequency was stabilized for more than 6 h in an open air environment without temperature control. The stabilized repetition rate has an in-loop tracking stability of 4.46×10(-13)/τ(1/2).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.39.002534DOI Listing
May 2014

Femtosecond amplifier similariton Yb:fiber laser at a 616 MHz repetition rate.

Opt Lett 2014 Apr;39(7):1831-3

We report a compact Yb:fiber ring laser operated at 616 MHz. The average output power is 450 mW at a pump power of 900 mW. The dechirped pulse width is 98 fs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.39.001831DOI Listing
April 2014

Tapered photonic crystal fiber for simplified Yb:fiber laser frequency comb with low pulse energy and robust f ceo singals.

Opt Express 2014 Jan;22(2):1835-41

A tapered silica photonic crystal fiber was designed and fabricated to generate more than one octave spanning supercontinuum (from 550 nm to 1400 nm at -30 dB level), by an input pulse of 40 fs 200 pJ directly from an Yb:fiber ring laser. The low pulse energy spectrum broadening are favorable to generate the high contrast f ceo signals with low noise. The f ceo signal with 40 dB signal-to-noise ratio was detected, which helps to build a compact real-world frequency comb.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.22.001835DOI Listing
January 2014

Molecular cloning and functional analysis of the fatty acid-binding protein (Sp-FABP) gene in the mud crab (Scylla paramamosain).

Genet Mol Biol 2013 Mar 4;36(1):140-7. Epub 2013 Mar 4.

College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.

Intracellular fatty acid-binding proteins (FABPs) are multifunctional cytosolic lipid-binding proteins found in vertebrates and invertebrates. In this work, we used RACE to obtain a full-length cDNA of Sp-FABP from the mud crab Scylla paramamosain. The open reading frame of the full length cDNA (886 bp) encoded a 136 amino acid polypeptide that showed high homology with related genes from other species. Real-time quantitative PCR identified variable levels of Sp-FABP transcripts in epidermis, eyestalk, gill, heart, hemocytes, hepatopancreas, muscle, ovary, stomach and thoracic ganglia. In ovaries, Sp-FABP expression increased gradually from stage I to stage IV of development and decreased in stage V. Sp-FABP transcripts in the hepatopancreas and hemocytes were up-regulated after a bacterial challenge with Vibrio alginnolyficus. These results suggest that Sp-FABP may be involved in the growth, reproduction and immunity of the mud crab.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1590/S1415-47572013005000007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3615520PMC
March 2013

Octave-spanning spectrum of femtosecond Yb:fiber ring laser at 528 MHz repetition rate in microstructured tellurite fiber.

Opt Express 2013 Feb;21(4):4703-8

State Key Laboratory of Advanced Optical Communication System and Networks, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China.

The octave-spanning spectrum was generated in a tellurite glass based microstructured fiber pumped by a 528 MHz repetition rate Yb:fiber ring laser without amplification. The laser achieved 40% output optical-to-optical efficiency with the output power of 410 mW. By adjusting the grating pair in the cavity, this oscillator can work at different cavity dispersion regimes with the shortest dechirped pulse width of 46 fs. The output pulses were then launched into a high-nonlinearity tellurite fiber, which has the zero-dispersion wavelength at ~1 μm. The high nonlinearity coefficient (1348 km⁻¹W⁻¹) and the matched zero-dispersion wavelength with pump laser enable the octave-spanning supercontinuum generated from 750 nm to 1700 nm with the coupled pulse energy above 10 pJ.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.21.004703DOI Listing
February 2013

Octave-spanning spectrum generation in tapered silica photonic crystal fiber by Yb:fiber ring laser above 500 MHz.

Opt Lett 2013 Feb;38(4):443-5

State Key Laboratory of Advanced Optical Communication System and Networks, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China.

We report octave-spanning spectrum generated in a tapered silica photonic crystal fiber by a mode-locked Yb:fiber ring laser at a repetition rate as high as 528 MHz. The output pulses from this laser were compressed to 62 fs. By controlling the hole expansion and core diameter, a silica PCF was tapered to 20 cm with an optimal d/Λ ratio of 0.6. Pulses with the energy of 280 pJ and the peak power of 4.5 kW were injected into the tapered fiber and the pulse spectrum was expanded from 500 to 1600 nm at the level of -30 dB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.38.000443DOI Listing
February 2013

750 MHz fundamental repetition rate femtosecond Yb:fiber ring laser.

Opt Lett 2013 Feb;38(3):314-6

State Key Laboratory of Advanced Optical Communication System and Networks, School of Electronics Engineering and Computer Science, Peking University, Beijing, China.

We report a compact Yb:fiber ring laser operated at 750 MHz. The average output power is 210 mW at a pump power of 1.8 W. The dechirped pulse width is 68 fs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.38.000314DOI Listing
February 2013

Characterization of the carrier envelope offset frequency from a 490 MHz Yb-fiber-ring laser.

Opt Express 2012 Jul;20(14):16017-22

State Key Laboratory of Advanced Optical Communication System and Networks, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, PR China.

We present the characterization of the carrier envelope offset frequency of 490 MHz femtosecond Yb-fiber ring laser. After amplification and compression, 1.7 W 90 fs pulses were produced for octave-span-spectrum generation from 600 nm to 1300 nm. More than 30 dB S/N ratio carrier envelope offset frequency signal was measured through a quasi-common-path interferometer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.20.016017DOI Listing
July 2012

Biochemical responses of the copepod Centropages tenuiremis to CO(2)-driven acidified seawater.

Water Sci Technol 2012 ;65(1):30-7

College of Oceanography and Environmental Science, Xiamen University, Xiamen 361005, China.

An ecophysiological experiment was conducted to examine the biochemical effects of acidified seawater containing elevated concentration of CO(2) (C(CO2) 0.08, 0.20, 0.50 and 1.00%) on the copepod Centropages tenuiremis. AchE, ATPase, SOD, GPx, GST, GSH level and GSH/GSSG ratio of the copepod were analyzed. The results showed that elevated C(CO2) and the duration of culture time significantly influenced several biochemical indices in C. tenuiremis (ATPase, GPx, GST, GSH and SOD). Furthermore, the principal component analysis results indicated that 72.32% of the overall variance was explained by the first three principal components (GPx, SOD and GSH). Changes in GPx and GSH levels may play a significant role in the antioxidant defense of copepods against seawater acidification. The long-term response of copepods to seawater acidification and the synergistic effects of acidification with other environmental factors, such as temperature, salinity and trace metal need further investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2166/wst.2011.821DOI Listing
March 2012

[Comparison of three protein extraction methods for proteomic analysis of Alexandrium tamarense with two-dimensional electrophoresis].

Wei Sheng Wu Xue Bao 2011 Aug;51(8):1113-8

State Key Laboratory for Marine Environmental Science, Xiamen University, Xiamen 361005, China.

Objective: In order to find the best extraction method for proteins of Alexandrium tamarense for two-dimensional electrophoresis (2-DE) analysis.

Methods: Three methods for extracting proteins from A. tamarense were compared, including trihydroxymethyl aminomethane (Tris-HCl ) buffer extraction, trichloroacetic acid (TCA)/acetone precipitation and lysis buffer extraction. Alga was cultivated in normal f/2 media (control) and supplemented with algicidal substances. Proteins obtained using the best extraction method were separated with 2-DE. Protein-expression differences were identified using matrix-assisted laser desorption/ionization-time of flight ( MALDI-TOF) mass spectrometry (MS).

Results: Among the three protein extraction methods, lysis buffer extraction shows the best detection of the number and quality of protein spots with a clear background. Then, the lysis buffer extraction method was successfully applied to profiling protein expression in algicidal substances stress conditions and 14 differential expression proteins were identified using MALDI-TOF/MS.

Conclusion: Lysis buffer extraction was the most effective protein extraction method for Alexandrium tamarense.
View Article and Find Full Text PDF

Download full-text PDF

Source
August 2011

Primary culture and characteristic morphologies of neurons from the cerebral ganglion of the mud crab, Scylla paramamosain.

In Vitro Cell Dev Biol Anim 2010 Sep 29;46(8):708-17. Epub 2010 Jun 29.

Department of Oceanography, Xiamen University, Xiamen, 361005, China.

Crustacean neurons, obtained from the cerebral ganglion of the mud crab Scylla paramamosain, were successfully cultured in vitro. They maintained typical morphological characteristics and showed better outgrowth in modified Medium 199 (M199) medium than that in Liebowitz's L-15 medium. Fetal bovine serum (FBS), muscle extracts, and hemolymph of the mud crab S. paramamosain were added as supplements. Only 20% FBS could promote neuron outgrowth, while muscle extracts and hemolymph of S. paramamosain did not improve neuron outgrowth. For cell dissociation, both collagenase type I and trypsin worked well as determined by initial cell viability and following cell outgrowth potential. More than six kinds of cells with different morphological characteristics were identified in the neuron outgrowth. They were "small cells", "veilers", "branchers", "multipolar cells", "super-large cell", and "bipolar cells". Among all of the cells, bipolar cells were identified for the first time in crustacean neurons culture and they could live longer than other cells. The neurons could grow for more than a week before retraction and eventual degradation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11626-010-9327-xDOI Listing
September 2010

The identification and distribution of progesterone receptors in the brain and thoracic ganglion in the mud crab Scylla paramamosain (Crustacea: Decapoda: Brachyura).

Invert Neurosci 2010 Nov 29;10(1):11-6. Epub 2010 Apr 29.

Department of Oceanography, State Key Laboratory of Marine Environmental Science, Xiamen University, 361005, Xiamen, China.

The existence of progesterone receptors (PR) in the Scylla paramamosain (mud crab) was studied using immunological techniques. By Western blotting, PR with an apparent molecular weight of 70 kDa is identified in both the brain and the thoracic ganglion. By immunohistochemistry, PR immunoreactive neurons are detected mainly in the protocerebrum, the subesophageal ganglion and the leg ganglion. PR immunoreactivity is localized mainly in the nuclei of these neurons, while only a few neurons show such activities in their cytoplasm. Our results provide evidence that progesterone modulates the neuroendocrine system mainly via nucleus receptors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10158-010-0100-3DOI Listing
November 2010

The effects of nickel on the reproductive ability of three different marine copepods.

Ecotoxicology 2010 Jun 25;19(5):911-6. Epub 2010 Feb 25.

College of Oceanography and Environmental Science, State Key Laboratory of Marine Environmental Science, Xiamen University, 361005, Xiamen, People's Republic of China.

Lethal and sublethal toxicity of Nickel (Ni) to three marine copepods Tigriopus japonicus, Apocyclops borneoensis and Acartia pacifica was investigated. The 48-h LC50 values were 17.70, 13.05 and 2.36 mg l(-1) Ni, respectively. A. pacifica was found to be the most sensitive to Ni in acute exposure tests. In order to assess sublethal effects of Ni on copepod reproduction, the test organisms were exposed to four nominal Ni concentrations 0, 10, 100, 1000 microg l(-1) Ni. The results indicated that offspring production of T. japonicus and A. borneoensis was significantly reduced after exposure to 10 microg l(-1) Ni. Whereas egg production and egg hatching success of A. pacifica were significantly reduced at 100 and 10 microg l(-1) Ni, respectively. Exposure of copepods to the highest Ni concentration caused a severely reduced nauplii production from T. japonicus, A. borneoensis and A. pacifica by 87.8, 56.9 and 65.8%, respectively, and a significantly reduced egg production of A. pacifica by 74.4%. These results show that Ni excess in the coastal environment can have detrimental effects on reproduction of copepods.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10646-010-0471-6DOI Listing
June 2010

Hepatopancreas cell cultures from mud crab, Scylla paramamosain.

In Vitro Cell Dev Biol Anim 2010 May 14;46(5):431-7. Epub 2009 Nov 14.

Department of Oceanography, Xiamen University, Xiamen, 361005, China.

Hepatopancreas is an important digestive and endocrine organ in crustacean. However, there are few reports on cell cultures from crabs. Here, the cell cultures of hepatopancreas from Scylla paramamosain was studied in vitro. Both the primary cell culture and subculture were grown in Leibovitz' L-15 medium, M199 medium, or a specially designed medium for S. paramamosain (MSP). The results showed that hepatopancreas cells in vitro grew in compact clusters in 2-3 d. Four types of cells could be identified. They were embryo cells, fibrillar cells, resorptive cells, and blister-like cells, respectively. Some of these cells could be subcultured for three generations. The MSP supported the best survival of these hepatopancreas cells, while M199 medium was the least effective of these three media. Fetal bovine serum and crab muscle extracts as supplements stimulated growth, but the crab hemolymph inhibited cell growth. Taken together, MSP is an appropriate medium for hepatopancreas cell cultures from S. paramamosain and can support cultures through several passages.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11626-009-9259-5DOI Listing
May 2010

Oxidative damage effects in the copepod Tigriopus japonicus Mori experimentally exposed to nickel.

Ecotoxicology 2010 Feb 26;19(2):273-84. Epub 2009 Sep 26.

College of Oceanography and Environmental Science, State Key Laboratory of Marine Environmental Science, Xiamen University, 361005, Xiamen, People's Republic of China.

Tigriopus japonicus Mori has been recognized as a good model for toxicological testing of marine pollutants. Recently, a large number of genes have been identified from this copepod, and their mRNA expression has been studied independently against exposure to marine pollutants; however, biochemical-response information is relatively scarce. The response of T. japonicus to nickel (Ni) additions was examined under laboratory-controlled conditions in 12 days exposure. Superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), acetylcholinesterase (AchE), reduced glutathione (GSH), the ratio of reduced to oxidized glutathione (GSH/GSSG) and metallothionein (MT) were analyzed for Ni treatments (0, 0.125, 0.25, 0.75 and 3.0 mg/L) after 1, 4, 7 and 12 days. The thiobarbituric reactive species assay was used to evaluate lipid peroxidation (LPO) level in copepods after exposure. The results showed that Ni remarkably affected the biochemical parameters (SOD, GPx, GST, GSH, and GSH/GSSG) after certain exposure durations. However, the copepod's LPO level was significantly decreased under metal treatments after exposure, hinting that the factors involved in LPO might not significantly depend on the operations and functions in the antioxidant system. Ni exhibited the neurotoxicity to copepods, because its use obviously elevated AchE activity. During exposure, Ni initially displayed an inhibition effect but induced MT synthesis in T. japonicus by day 12, probably being responsible for metal detoxification. Thus, Ni had intervened in the detoxification process and antioxidant system of this copepod, and it could be used as a suitable bioindicator of Ni exposure via measuring SOD, GPx, GST, and MT as biomarkers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10646-009-0410-6DOI Listing
February 2010

Applying proteomic methodologies to analyze the effect of hexamethylene bisacetamide (HMBA) on proliferation and differentiation of human gastric carcinoma BGC-823 cells.

Int J Biochem Cell Biol 2004 Aug;36(8):1613-23

Department of Biology, Center for Proteomics, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, PR China.

Human gastric carcinoma BGC-823 cells underwent morphological differentiation and cell cycle arrest in vitro when treated with 5mM hexamethylene bisacetamide (HMBA) for 48h. To further understand the mechanism of HMBA-induced differentiation, proteomic methodologies were applied to screen and identify altered proteins involved in the commitment of BGC-823 cells to differentiate. Five distinct altered proteins were acquired by two-dimensional (2-D) PAGE and were consequently identified as ras-related protein rab-35 (Rab-35), splice truncated isoform of transmembrane protease, serine 3 (serine TADG-12), regulator of G-protein signaling 1 (RGS1), ret finger protein-like 1 (RFPL1) and F-actin capping protein alpha-3 subunit (GSG3) by analysis of mass spectrograph. Of the five proteins, serine TADG-12 down-regulated under the detectable level after HMBA treatment, Rab-35, RGS1 and RFPL1 sharply up-regulated within the HMBA-induced BGC-823 cells, and GSG3, appearing in both treated and untreated cells, remarkably increased within BGC-823 cells after HMBA stimulation. Our results implicate that the molecular mechanism of BGC-823 cell differentiation in response to HMBA may involved in complex processes including a signaling network linking vesicle transport, actin cytoskeleton remodeling except for morphology differentiation, cell cycle G1 arrest.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biocel.2004.01.021DOI Listing
August 2004

Universal primer PCR with DGGE for rapid detection of bacterial pathogens.

J Microbiol Methods 2004 Jun;57(3):409-13

Department of Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, PR China.

A universal primer PCR (UPPCR) combined with denaturing gradient gel electrophoresis (DGGE) was evaluated as a method permitting the rapid detection of pathogens. The results show that this method is efficient at amplifying the conserved regions of bacterial 16S rRNA genes with universal primers and can detect causative bacterial pathogens rapidly. Six species of bacteria from fisheries (Pseudomonas fluorescens, Vibrio anguillarum, Aeromonas hydrophila, Vibrio fluvialis, Providencia rettgeri and Aeromonas sobria) were examined. Our results indicate that the approach we undertook can be adopted not only for axenic bacterial populations but also for mixed communities as well. Furthermore, we were able to achieve the rapid detection of multiple bacteria a single in sample. In addition, UPPCR-DGGE was shown to be better than previously reported UPPCR-single-stranded conformation polymorphism (SSCP)-based methods for the rapid detection of bacterial pathogens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mimet.2004.02.010DOI Listing
June 2004