Publications by authors named "Zhi-xun Guo"

Article Synopsis
  • Scylla paramamosain, an important crab species in aquaculture, is increasingly threatened by the highly pathogenic mud crab dicistrovirus-1 (MCDV-1), which disrupts its cultivation due to viral diseases.
  • A study analyzed the immune response of infected mud crabs, revealing 5,139 differentially expressed genes and highlighting pathways related to humoral immunity that the crabs activate to combat MCDV-1, while also showing disruptions in metabolic processes.
  • The research identified 9 key hub genes linked to viral endocytosis, indicating that MCDV-1 may utilize this process to enter crab cells and replicate, marking a significant step in understanding the viral
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Laminin receptor (LR), which mediating cell adhesion to the extracellular matrix, plays a crucial role in cell signaling and regulatory functions. In the present study, a laminin receptor gene (SpLR) was cloned and characterized from the mud crab (Scylla paramamosain). The full length of SpLR contained an open reading frame (ORF) of 960 bp encoding 319 amino acids, a 5' untranslated region (UTR) of 66 bp and a 3' UTR of 49 bp.

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Hypoxia-inducible factors -1 (HIF-1) is a crucial transcription factor that regulates the expression of glycolytic genes. Our previous study proved that the Mud crab dicistrovirus-1 (MCDV-1) can induce aerobic glycolysis that favors viral replication in mud crab Scylla paramamosain. However, the role of HIF-1 on key glycolytic genes during the MCDV-1 infection has not been examined.

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Activating transcription factor 6 (ATF6) is critical for regulation of unfolded protein response (UPR), which is involved in the endoplasmic reticulum (ER) proteostasis maintenance and cellular redox regulation. In the present study, a ATF6 gene from the mud crab (designated as Sp-ATF6) has been cloned and identified. The open reading frame of Sp-ATF6 was 1917 bp, encoding a protein of 638 amino acids.

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Heat shock proteins play an important role in host defense, and modulate immune responses against pathogen infection. In this study, a novel HSC70 from the mud crab (designated as SpHSC70) was cloned and characterized. The full length of SpHSC70 contained a 58 bp 5'untranslated region (UTR), an open reading frame (ORF) of 2,046 bp and a 3'UTR of 341 bp.

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Article Synopsis
  • Prolyl hydroxylase 2 (PHD2) serves as the main oxygen sensor regulating HIF-1α stability, and researchers identified a novel PHD2 gene called SpPHD2 from the mud crab Scylla paramamosain, revealing its full transcript length of 1926 bp.
  • The SpPHD2 protein features key structural domains and is broadly expressed in various tissues, with its localization primarily in the cytoplasm.
  • Silencing SpPHD2 increased levels of SpHIF-1α and associated genes, while overexpression decreased SpHIF-1α activity; additionally, SpPHD2 expression rises under low oxygen conditions, suggesting a feedback loop in regulating hypoxia responses.
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The transcription factor Nrf2 plays vital roles in detoxification and antioxidant enzymes against oxidative stress. However, the function of Nrf2 in crustaceans is not well studied. In this study, a novel Nrf2 gene from the mud crab (Sp-Nrf2) was identified.

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Cadmium is one of hazardous pollutants that has a great threat to aquatic organisms and ecosystems. The intestine plays important roles in barrier function and immunity to defend against environmental stress. However, whether cadmium exposure caused the intestine injury is not well studied.

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Cytochrome P450 (CYPs) enzymes are one of the critical detoxification enzymes, playing a key role in antioxidant defense. However, the information of CYPs cDNA sequences and their functions are lacked in crustaceans. In this study, a novel full-length of CYP2 from the mud crab (designated as Sp-CYP2) was cloned and characterized.

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Glutaredoxin (Grx) is a glutathione-dependent oxidoreductase that plays a key role in antioxidant defense. In this study, a novel Grx2 gene (SpGrx2) was identified from the mud crab Scylla paramamosain, which consists of a 196 bp 5' untranslated region, a 357 bp open reading frame, and a 964 bp 3' untranslated region. The putative SpGrx2 protein has a typical single Grx domain with the active center sequence C-P-Y-C.

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Hypoxia is a major environmental stressor that can damage the oxidation metabolism of crustaceans. Glutaredoxin (Grx) is a key member of the thioredoxin superfamily and plays an important role in the host's defense against oxidative stress. At present, the role of Grx in response to hypoxia in crustaceans remains unclear.

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Article Synopsis
  • * The study successfully cloned and characterized a new variant of Grx (Sp-Grx 5) in mud crabs, revealing it to have a unique sequence and high expression levels in specific tissues like the hepatopancreas.
  • * Sp-Grx 5 expression increases significantly when crabs face stressors like infection or toxins, indicating its involvement in immune response and detoxification, while also enhancing cell survival under oxidative stress.
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Mud crab reovirus (MCRV) is a serious pathogen that leads to large economic losses in the mud crab farming. However, the molecular mechanism of the immune response after MCRV infection is unclear. In the present study, physiological, transcriptomic, and metabolomic responses after MCRV infection were investigated.

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Article Synopsis
  • Phosphofructokinase (PFK) is a crucial enzyme in glycolysis, and researchers have cloned and studied a specific PFK gene (SpPFK) from the mud crab Scylla paramamosain.
  • The SpPFK gene consists of 249 bp of 5' UTR, a 2,859 bp open reading frame, and 1,248 bp of 3' UTR, with high expression levels in the gill, hemocytes, and muscle, especially after infection with mud crab dicistrovirus-1 (MCDV-1).
  • Knocking down SpPFK through RNA interference was shown to lower lactate dehydrogenase levels, enhance survival rates in
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can cause infections and diseases in a variety of marine vertebrates and invertebrates, which are harmful to the aquaculture industry. The LuxS quorum-sensing system regulates the expression of virulence factors in a wide variety of pathogenic bacteria. In this study, an in-frame deletion of the gene was constructed to reveal the role of LuxS in the physiology and virulence of .

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Article Synopsis
  • Apoptosis is crucial for the immune defense against infections, and caspase 3, a family of proteins, plays a key role in this process.
  • The full-length caspase 3 from mud crab (Sp-caspase 3) was cloned, characterized, and found to be expressed widely, especially in hemocytes, with its activity located in both the cytoplasm and nucleus.
  • Over-expressing Sp-caspase 3 can induce cell death and its expression increases during infection with V. Parahaemolyticus, while knocking it down reduces apoptosis and increases crab mortality.
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Oxidative stress is considered as the toxicity mechanism of environmental stressors on aquatic organisms. This study aims to explore the effects of oxidative stress on physiological responses, DNA damage and transcriptional profiles of the mud crabs Scylla paramamosain. In the present study, mud crabs were injected with 0.

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Mud crab (Scylla paramamosain) is an economically important cultured species in China. Hypoxia is a major environmental stressor during mud crab culture. In the present study, we investigated the oxidative stress and transcriptome changes in the gills of mud crab after intermediate hypoxia stress with dissolved oxygen (DO) 3.

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Article Synopsis
  • The study identified and characterized the p53 gene (Sp-53) in the mud crab, showing it is vital for DNA repair, cell cycle regulation, and maintaining genetic stability.
  • Sp-53 is expressed in all tissues, especially in the hepatopancreas and hemocytes, and its expression increases significantly after infection with Vibrio parahaemolyticus, leading to oxidative stress and DNA damage.
  • Knocking down Sp-53 through RNA interference resulted in lower antioxidant and apoptosis-related gene expression, higher crab mortality, and increased DNA damage, indicating Sp-53's crucial role in managing infections and cellular damage.
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Cadmium is one of the most common heavy metal pollutants in the aquatic environment. Mud crab (Scylla paramamosain) is considered a model organism to monitor the impact of heavy metals. However, knowledge about toxicological mechanism of cadmium in crustaceans still remains limited.

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Mud crab (Scylla paramamosain) is an important economic species in China. Vibrio parahaemolyticus infection have caused a great economic loss in mud crab farming. The mechanism involved in the immune responses of mud crab to V.

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Article Synopsis
  • Researchers examined how mud crabs (Scylla paramamosain) respond physiologically and immunologically to being exposed to air.
  • Air exposure led to increased levels of certain plasma enzymes (AST, ALT, ALP) and elevated glucose and malondialdehyde levels, indicating stress.
  • Key proteins and signals, including SOD, CAT, HSP90, HSP70, and HIF-1, were activated, showing oxidative stress was a factor, especially after prolonged air exposure, with notable fluctuations in caspase-3 levels over time.
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Glutathione peroxidases (GPx) are parts of the enzymatic antioxidant system that can eliminate the peroxides produced as effect of reactions of molecules with reactive oxygen species (ROS). In this study, a selenium-dependent glutathione peroxidase 3 cDNAs (designated as SpGPx3) was obtained from the mud crab Scylla paramamosain. The open reading frame (ORF) of SpGPx3 was 639 bp, which encoded a putative protein of 212 amino acids.

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The mud crab, Scylla paramamosain, is an economically-important crab in China. Air exposure is an important environmental stressor during mud crab culture and transportation. Adaptive mechanisms responding to air exposure in mud crabs are still poorly understood.

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Glutathione S-transferase (GST) plays important roles in cellular detoxification and antioxidant defense. A Mu-type glutathione S-transferase (designated as SpMu-GST) was obtained from the mud crab Scylla paramamosain. The open reading frame of SpMu-GST was comprised a 690 bp, which encoded a putative protein of 229 amino acids.

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