Zhitao Qi

Effects of Dietary Administration of Chlorella on the Immune Status of Gibel Carp, Carassius Auratus Gibelio

In the present study the effects of dietary Chlorella on the immune status of gibel carp, Carassius auratus gibelio, were evaluated. A total of 540 healthy fish were divided into 6 groups, with one control group fed with Chlorella-free diet and five experimental groups fed diets supplemented with 0.4 to 2.0% Chlorella. The whole trial lasted 60 days. At the end of the trial, the weight gain and immune parameters of fish were analysed. Results showed that Chlorella could increase the levels of immunoglobulin M and D, interleukin-22 and chemokine (C-C motif) ligand 5 in some tissues, which indicated that dietary Chlorella can be involved in regulating adaptive and innate immunity.

Cloning and Expression of β-Defensin from Soiny Mullet (Liza haematocheila), with Insights of its Antibacterial Mechanism

Beta-defensins are important part of innate immunity of fish, which are the first defense line against invading pathogens. In this study, the β-defensin (Lhβ-defensin) gene was cloned from spleen tissue of soiny mullet (Liza haematocheila). Lhβ-defensin cDNA was 747 bp in length, encoding 63 amino acids. Sequence alignment revealed that Lhβ-defensin contained six conserved cysteine residues and shared 97.5% sequence identities with grouper (Epinephelus coioides) β-defensin. Realtime PCR revealed that Lhβ-defensin was highest expressed in the immune related organs, such as spleen, kidney and gut of healthy fish. Following Streptococcus dysgalactiae infection, Lhβ-defensin was up-regulated in immune related organs, e.g. 17.6-fold in spleen and 10.87-fold in gut at 24 h post infection (hpi). Lhβ-defensin possessed a monomeric structure of a three-stranded anti-parallel β-sheet and an α-helix stabilized by three disulfide bonds formed by Cys30-Cys58, Cys36-Cys52, and Cys40-Cys59. In addition to the experimental work, computer simulation was also carried out to determine the possible conformation of β-defensin and its interaction with palmitoyloleoylphosphatidylglycerol (POPG), a model of bacteria membrane. The Lhβ-defensin was found to form dimeric structure stabilized by the van der Waals contacts of Leu35 and Cys37 in two anti-parallel β1-strands and the cation-π interaction between Tyr32 and Arg54 respectively in the two β1-strands. The most important interactions between β-defensin and membrane are the electrostatic interactions between Arg residues in β-defensin and head group of POPG bilayer as well as hydrogen bond interactions between them. Our results were useful for further understanding the potential mechanism of antimicrobial property of fish β-defensins.

Changes of globins expression in tongue sole, Cynoglossus semilaevis (Actinopterygii: Pleuronectiformes: Cynoglossidae) in response to short-term hypoxia

Aquatic hypoxia, a complex ecological phenomenon, can cause major metabolic changes and influence foetal growth and development of all organisms living in water (Kajimura et al. 2004). With the increased industrialization and urbanization of coastal zones in recent years, hypoxia has grown strikingly in aquatic systems and has received much attention in biomedical research (Gray et al. 2002, Wawrowski et al. 2011). Fishes are the main aquatic animals that are first affected by hypoxia, and so fishes have become a prime model to investigate hypoxia tolerance strategies at the organism level (Roesner et al. 2008). Under hypoxia, a variety of physiological, anatomical and behavioural mechanisms were activated in fish that enables fish to survive in this condition. One of the main mechanisms relies on the globins to enhance the O2 transport capacitance, facilitate intracellular O2 diffusion, or enable O2 storage for hypoxia. To date, many types of globins have been identified in vertebrates. Hemoglobin (Hb) is a heterotetramer that consists of two α and two β chains. Hb is located in the erythrocytes and serves for the transport of O2. Myoglobin (Mb) is a monomeric protein and mainly included in the myocytes of the heart and skeletal muscles to store oxygen and to facilitate intracellular oxygen diffusion (Wittenberg and Wittenberg 2003). Neuroglobin (Ngb) is mainly resided in the central and peripheral nervous system (Burmester et al. 2000) and may supply O2 to metabolically active neurons. Cytoglobin (Cygb) is expressed in the fibroblast cells and distinct neurons, and may be involved in reactive oxygen species detoxications or in the function of supplying oxygen to particular enzymatic reactions (Burmester et al. 2002, Schmidt et al. 2004). Those four globins (Hb, Mb, Ngb, and Cygb) have been ACTA ICHTHYOLOGICA ET PISCATORIA (2011) 41 (3): 179–184 DOI: 10.3750/AIP2011.41.3.05

Structural insights into ligand binding of PGRP1 splice variants in Chinese giant salamander (Andrias davidianus) from molecular dynamics and free energy calculations

Peptidoglycan (PGN) recognition proteins (PGRPs) are important pattern recognition receptors of the innate immune system. A number of PGRP splicing variants produced by alternative splicing of PGRP genes have been reported. However, several important aspects of interactions between PGRP splice variants and their ligands are still unclear. In the present study, three dimensional models of salamander PGRP1 (adPGRP1) and its splice variant (adPGRP1a) were constructed, and their key amino acids involved in interacting with PGNs were analyzed. The results revealed that adPGRP1a has a typical PGRPs structure containing five β-sheets and four α-helices, while adPGRP1 contained five β-sheets and only one α-helix due to the lack of 51 amino acids at its C-terminus. Molecular docking revealed that van der Waals and Coulombic interactions contributed to interactions in the protein–ligand complex. Further binding energy of adPGRP-PGNs computed by the MM-PBSA method revealed that adPGRP1a and adPGRP1 might selectively bind to different PGNs; the former might selectively bind Dap-type PGNs and the latter both types of PGNs. In addition, the binding energy of each residue of adPGRP1a and adPGRP1 was also calculated, revealing that residues involved in the interaction of protein–ligand complexes were different in adPGRP1a and adPGRP1. These results provided a first insight into the potential basis for interaction between PGRPs generated by alternative splicing and PGN derivatives.

De Novo Assembly and Characterization of Transcriptome in Somatic Muscles of the Polychaete Perinereis aibuhitensis

ABSTRACT Lv, F.; Wang, T.; Liu, F.; Yebing, Y.; Qiao, G.; Wang, Z., and Qi, Z., 2017. De novo assembly and characterization of transcriptome in somatic muscles of the polychaete Perinereis aibuhitensis. The polychaete Perinereis aibuhitensis is a common species distributed throughout coastal and estuarine regions with growing importance in aquaculture. However, the knowledge of molecular mechanism of physiology and pathology of this polychaete has been limited. In this study, the transcriptome of somatic muscles of P. aibuhitensis was sequenced using the Illumina HisSeq 2000 sequencing platform. As a result, 53,204 unigenes with a length of 63,967,647 base pairs (bp) were obtained, among which 29,797, 9951, and 24,844 unigenes were matched in the nonredundant, nucleotide, and Swiss-Prot databases, respectively. Gene ontology analysis revealed that 9938 unigenes were classified into three categories: biological process, cellular component, and molecular function. In addition, 21,756 unigenes were grouped into 257 annotated pathways in the Kyoto Encyclopedia of Genes and Genomes database. More importantly, genes involved in fatty acid biosynthesis and metabolism, muscle contraction, and innate immunity of P. aibuhitensis were analyzed in detail. In addition, 4682 simple sequence repeats and 32,202 candidate single nucleotide polymorphisms were identified from the P. aibuhitensis transcriptome. These data facilitate further studies of the physiology and molecular response of P. aibuhitensis. Furthermore, these results contribute to the molecular basis for coastal research worldwide, using P. aibuhitensis as a model animal in the fields of environmental ecology, toxicology, etc.

Growth and antioxidant status of oriental river prawn Macrobrachium nipponense fed with diets containing vitamin E

A feeding trial was carried out to investigate the dietary vitamin E requirement of the oriental river prawn Macrobrachium nipponense (weight of 0.3–0.4 g) and its effect role on antioxidant activity. Prawns were fed with seven levels of vitamin E (0, 25, 50, 75, 100, 200, and 400 mg/kg diet) for 60 days. The results show that dietary vitamin E supplementation could significantly increased the prawn weight (P < 0.05). The activity of superoxide dismutase (SOD) in the hepatopancreas was significantly higher in prawns fed with diets supplemented with ≤75 mg/kg vitamin E than in those fed with diets supplemented with 100–400 mg/kg vitamin E (P < 0.05). The activity of catalase (CAT) in the hepatopancreas decreased significantly as dietary vitamin E supplementation increased (P < 0.05), and no significant difference was detected in glutathione peroxidase (GSH-Px) activity between different dietary groups (P >0.05). The contents of vitamin E in the hepatopancreas and in the muscle increased with increasing dietary vitamin E. There was a linear correlation between the vitamin E level in diet and that in muscle, and between the vitamin E level in diet and that in the hepatopancreas. All the above results indicated that dietary vitamin E can be stored in the hepatopancreas and muscle and lower both the activities of SOD and CAT in the hepatopancreas, suggesting that it is a potential antioxidant in M. nipponense. Broken line analysis conducted on the weight gains of prawns in each diet group showed that the dietary vitamin E requirement for maximum growth is 94.10 mg/kg.

Effects of β-TCP ceramics on osteoblast cellular proliferating, mineralization and osteocalcin expression

After co-cultrured osteoblast with β-TCP ceramics, the cellular proliferating, mineralization and osteocalcin expression were studied. MTT assay showed that β-TCP ceramics had no affect on cellular proliferating. Laser scanning confocal detection showed that β-TCP ceramics could increase the mineralization level of osteoblast. Furthermore, RT-PCR showed that β-TCP could increase the expression level of osteocalcin. Those results indicate β-TCP ceramics had perfect biocompatibility and increased the mineralization of osteoblast to accelerate osteogenesis by means of affecting the expression of genes involving in osteogeneticprocess.