Effects of magnetic water and feeding rate on growth performance and immunity of Nile Tilapia (Oreochromis niloticus)

Objective: The present study was designed to investigate the effect of magnetic water treatment technique and different feeding rates on growth performance, feed utilization, water quality parameters, chemical composition and intestinal histomorphometric parameters of monosex Nile tilapia (Oreochromis niloticus).Design: Experimental study with a factorial design.Fish: A total of 2880 apparently healthy monosex Nile tilapia (O. niloticus) with an average initial body weight of 69.86 ± 0.8 g were randomly distributed into 18 concreate ponds.Procedures: Experimental fish were fed on commercial diet (30.1% protein and 4600 Kcal GE/kg diet) based on three levels of feeding rate 3, 4 and 5% from fish biomass for both treated and control groups. Water was treated with magnetic waves at 0.2 Tesla (Tesla= 2000 Gauss) compared to the control group water (zero Tesla). Growth performance parameters, feed utilization, chemical composition and intestinal morphometric analysis were calculated in all groups at the end of the experiment after eight weeks.Results: The results indicated that growth performance, feed utilization and intestinal histomorphometric analyses improved significantly (P<0.01) in magnetic water groups compared to control groups at the three levels of feeding rate. In addition, water physicochemical parameters including Ammonia (NH4), Nitrate (NO3), Nitrite (NO2), PH and dissolved oxygen (DO) significantly improved in magnetic water treated groups at the three feeding rate levels.Conclusions and clinical relevance: In conclusion, magnetic treatment of water could improve water quality parameters, fish growth performance, feed utilization, and intestinal histomorphometric analyses at different feeding rate

Metabolomic Analyses, Toxicity Biomarkers and Histopathological Changes in the Liver of Nile Tilapia Exposed to Diazinon Toxicity

This study was undertaken to screen for some biomarkers of toxicity in the liver of Nile tilapia fish during subacute Diazinon toxicity (0.28 mgL-1 for 25 days) by using Targeted metabolomics analyses and quantitatively measure 17 amino acids, and also to monitor antioxidant status of liver (glutathione, peroxidase, catalase, superoxide dismutase and malondialdehyde). There were significant increases in branched chain amino acids valine, leucine and isoleucine (p>0.01, p>0.05and p>0.01) respectively. There was a significant increase in phenylalanine (an aromatic amino acid) P>0.05, a significant increase in lipid peroxidation (malondialdehyde P>0.001), and significant decreases in the activity of antioxidant enzymes (SOD, CAT, GSH-px) with p values (P>0.01, P>0.01, and P> 0.001) respectively. Histopathological examination showed diffuse hepatocellular necrosis with multifocal granuloma and massive hepatocellular vacuolation with congested sinusoids. It can be concluded that subacute toxicity of DZN in Nile tilapia is involved in proliferation and growth of tumor cells and negatively affects the antioxidant status of the liver

The efficiency of zinc sulfate immersion bath on improved wound healing via promoting antioxidant activity, gene expression biomarkers, and skin re-epithelization in a common carp-induced wound model

Abstract The experiment was designed to examine the influence of employing three doses of ZnSO4 on the wound healing process in partially scaled common carp. A total of 240 healthy common carp fish (52.3 ± 0.9 g) were randomly allocated into four equal groups in triplicate (20 each). The first group left without any zinc sulfate treatment and served as a control group, while the second group through the fourth group were immersed in a zinc sulfate bath at a dose of 2.09, 1.05, and 0.53 mg/L corresponding to 1/5, 1/10, and 1/20 of 96 h LC50 of Zn, (Zn/5, Zn/10, and Zn/20, respectively). After wound induction, tissue specimens were collected within three different intervals (6 h, 24 h, 72 h, and 14 days). The results indicated that the Zn/5 fish group induced doubled folding increments in the expression of transforming growth factor (TGF)‐β1 after 6 h compared to other groups, whereas collagen type I alpha 1 (COL1α1) and metallothionein (Met) genes exhibited a triple folding increment compared to Zn/10 and a fivefold increase compared to control after two days of wound induction. Moreover, vascular endothelial growth factor (VEGF)‐A and fibroblast growth factor (FGF)‐7 genes showed a dose-dependent manner of expression at all examined points after wound induction. Also, all estimated antioxidant biomarker (superoxide-dismutase, SOD; catalase, CAT; glutathione, GSH; and malonaldehyde, MDA) activities were boosted in the Zn/5 group till three days of wound induction compared to all groups. In addition, the reepithelization score and histological alteration results revealed clear improvement in the Zn/5 group, as most muscle fibers appeared regular, straight, and parallel arranged. In contrast, other groups exhibited a detectable limited area of disrupted muscle fibers. Finally, it could be concluded that the ZnSO4 immersion bath at 1/5 of the calculated LC50 effectively enhanced the healing process and skin reepithelization

Functional analysis of membrane-bound complement regulatory protein on T-cell immune response in ginbuna crucian carp

Complements have long been considered to be a pivotal component in innate immunity. Recent researches, however, highlight novel roles of complements in T-cell-mediated adaptive immunity. Membrane-bound complement regulatory protein CD46, a costimulatory protein for T cells, is a key molecule for T-cell immunomodulation. Teleost CD46-like molecule, termed Tecrem, has been newly identified in common carp and shown to function as a complement regulator. However, it remains unclear whether Tecrem is involved in T-cell immune response. We investigated Tecrem function related to T-cell responses in ginbuna crucian carp. Ginbuna Tecrem (gTecrem) proteins were detected by immunoprecipitation using anti-common carp Tecrem monoclonal antibody (mAb) and were ubiquitously expressed on blood cells including CD8α^+ and CD4^+ lymphocytes. gTecrem expression on leucocyte surface was enhanced after stimulation with the T-cell mitogen, phytohaemagglutinin (PHA). Coculture with the anti-Tecrem mAb significantly inhibited the proliferative activity of PHA-stimulated peripheral blood lymphocytes, suggesting that cross-linking of Tecrems on T-cells interferes with a signal transduction pathway for T-cell activation. These findings indicate that Tecrem may act as a T-cell moderator and imply that the complement system in teleost, as well as mammals, plays an important role for linking adaptive and innate immunity.Published version is available for viewing only. (See "Related DOI")「関連DOI」より出版社版の閲覧専用ページへリン

Identification of Immune Relevant Genes Using Expressed Sequence Tags (ESTs) in Common carp (Cyprinus carpio) Gills and Intestine

Identification of immune related molecules that function in fish organs is important for better understanding of the host defense mechanisms in fish. Expressed sequence tags (ESTs) represent the expressed portion of a genome, so they have proven to be useful tool for gene identification and confirmation of gene predictions. In the present study, a transcriptome analysis of carp gill and intestine EST libraries have been done as an attempt to identify the immune relevant genes expressed in those organs. A total of 2148 EST clones were generated from the two libraries: 1099 clones from gill library in which 632 clones were matched with functional proteins and 1049 clones from intestine library in which 559 clones were matched with functional proteins. The results of gill EST library has more frequency of innate immune–molecules containing MHC class I and MHC class II, which showed 18.3% of the immune molecules than those in intestine library which represents 10.8% only. The gill library also showed higher frequency of the cytokines and chemokine molecules and/or their receptors compared to the intestine library

Molecular evidence for the existence of two distinct IL-8 lineages of teleost CXC-chemokines

Interleukin-8 (IL-8) is a CXC-type chemokine with a chemotactic activity mainly on neutrophils and plays a key role in promoting inflammation. In teleosts, several CXC-chemokines have been cloned and characterized as being IL-8-like. Phylogenetic data however indicate that the reported teleost IL-8-like chemokines are substantially remote from mammalian IL-8, forming a fish-specific clade of IL-8-like chemokines distinct from that of tetrapod IL-8. In the present study, a novel IL-8-like chemokine, designated CaIL-8, has been found in the expressed sequence tags of carp gills and identified as an orthologue of mammalian IL-8. The CaIL-8 transcript encodes 99 amino acids containing a typical CXC motif but lacks an ELR motif, as in most teleost IL-8-like chemokines. Phylogenetic tree constructed by the maximum likelihood method suggests a closer relationship of CaIL-8 with mammalian IL-8 than with other teleost CXC-chemokines reported to be IL-8-like. In a normal unstimulated carp, CaIL-8 mRNA was detected by RT-PCR only in gills, kidney, spleen, heart and peripheral blood leukocytes, in contrast to a previously reported carp IL-8-like chemokine CXCa, which shows ubiquitous basal expression. The results, taken together, are strongly indicative of the presence of two major IL-8-like lineages of CXC-chemokines in teleost.Published version is available for viewing only. (See "Related DOI")「関連DOI」より出版社版の閲覧専用ページへリン