Bioinformatics characteristics and expression analysis of IL-8 and IL-10 in largemouth bass (Micropterus salmoides) upon Nocardia seriolae infection.

IL-8 and IL-10 are crucial inflammatory cytokines that participate in defending host cells against infections. To demonstrate the function of the two interleukin genes in largemouth bass (Micropterus salmoides), we initially cloned and identified the cDNA sequences of il-8 and il-10 in largemouth bass, referred to as Msil-8 and Msil-10, respectively. The open reading frame (ORF) of Msil-8 was 324 bp in length, encoding 107 amino acids, while the ORF of Msil-10 consisted of 726 bp and encoded 241 amino acids. Furthermore, the functional domains of the SCY domain in MsIL-8 and the IL-10 family signature motif in MsIL-10 were highly conserved across vertebrates. Additionally, both MsIL-8 and MsIL-10 showed close relationships with M. dolomieu. Constitutive expression of Msil-8 and Msil-10 was observed in various tissues, with the highest level found in the head kidney. Subsequently, largemouth bass were infected with Nocardia seriolae via intraperitoneal injection to gain a further understanding of the function of these two genes. Bacterial loads were initially detected in the foregut, followed by the midgut, hindgut, and liver. The mRNA expression of Msil-8 was significantly down-regulated after infection, especially at 2 days post-infection (DPI), with a similar expression to Msil-10. In contrast, the expression of Msil-8 and Msil-10 was significantly upregulated in the foregut at 14 DPI. Taken together, these results reveal that the function of IL-8 and IL-10 was likely hindered by N. seriolae, which promoted bacterial proliferation and intercellular diffusion.

Sound attenuation at low to mid frequencies in low velocity seabottoms.

Attenuation is the most difficult seafloor acoustic property to get, particularly at low to mid frequencies. For low velocity bottoms (LVB), it becomes even more challenging, due to its small attenuation and lower velocity (relative to the velocity of the adjacent water). The latter one causes a fatal "seafloor velocity-attenuation couplings" in geo-acoustic inversions. Thus, attenuation inversions for the LVB require an accurate seafloor velocity profile, especially the velocity in the LVB layer. The propagation of explosive sound in the Yellow Sea with a strong thermocline and a top LVB layer exhibits many prominent characteristics: modal dispersion (the ground wave, water wave, Airy phase), two groups of water waves at high frequencies, and the siphon effect which causes abnormally large sound transmission loss at selected frequencies, etc. These observations are used to precisely measure the critical frequency, the Airy frequency, Airy wave velocity, 1st mode group velocity, and to derive the velocities in the LVB layer and in the basement. Using inverted seafloor parameters, the source level-normalized transmission loss and the first mode decay rate in ranges up to 27.66 km, the sound attenuations in the LVB are derived for a frequency range of 13-5000 Hz.

Selenium deficiency-induced high concentration of reactive oxygen species restricts hypertrophic growth of skeletal muscle in juvenile zebrafish by suppressing TORC1-mediated protein synthesis.

Se deficiency causes impaired growth of fish skeletal muscle due to the retarded hypertrophy of muscle fibres. However, the inner mechanisms remain unclear. According to our previous researches, we infer this phenomenon is associated with Se deficiency-induced high concentration of reactive oxygen species (ROS), which could suppress the target of rapamycin complex 1 (TORC1) pathway-mediated protein synthesis by inhibiting protein kinase B (Akt), an upstream protein of TORC1. To test this hypothesis, juvenile zebrafish (45 d post-fertilisation) were fed a basal Se-adequate diet or a basal Se-deficient diet or them supplemented with an antioxidant (DL-α-tocopherol acetate, designed as VE) or a TOR activator (MHY1485) for 30 d. Zebrafish fed Se-deficient diets exhibited a clear Se-deficient status in skeletal muscle, which was not influenced by dietary VE and MHY1485. Se deficiency significantly elevated ROS concentrations, inhibited Akt activity and TORC1 pathway, suppressed protein synthesis in skeletal muscle, and impaired hypertrophy of skeletal muscle fibres. However, these negative effects of Se deficiency were partly (except that on ROS concentration) alleviated by dietary MHY1485 and completely alleviated by dietary VE. These data strongly support our speculation that Se deficiency-induced high concentration of ROS exerts a clear inhibiting effect on TORC1 pathway-mediated protein synthesis by regulating Akt activity, thereby restricting the hypertrophy of skeletal muscle fibres in fish. Our findings provide a mechanistic explanation for Se deficiency-caused retardation of fish skeletal muscle growth, contributing to a better understanding of the nutritional necessity and regulatory mechanisms of Se in fish muscle physiology.

Molecular characterization and expression analysis of selenoprotein W gene in rainbow trout (Oncorhynchus mykiss) with dietary selenium levels.

Selenium (Se) plays an essential role in the growth of fish and performs its physiological functions mainly through incorporation into selenoproteins. Our previous studies suggested that the selenoprotein W gene (selenow) is sensitive to changes in dietary Se in rainbow trout. However, the molecular characterization and tissue expression pattern of selenow are still unknown. Here, we revealed the molecular characterization, the tissue expression pattern of rainbow trout selenow and analyzed its response to dietary Se. The open reading frame (ORF) of the selenow gene was composed of 393 base pairs (bp) and encodes a 130-amino-acid protein. The 3' untranslated region (UTR) was 372 bp with a selenocysteine insertion sequence (SECIS) element. Remarkably, the rainbow trout selenow gene sequence was longer than those reported for mammals and most other fish. A ß1-α1-ß2-ß3-ß4-α2 pattern made up the secondary structure of SELENOW. Furthermore, multiple sequence alignment revealed that rainbow trout SELENOW showed a high level of identity with SELENOW from Salmo salar. In addition, the selenow gene was ubiquitously distributed in 13 tissues with various abundances and was predominantly expressed in muscle and brain. Interestingly, dietary Se significantly increased selenow mRNA expression in muscle. Our results highlight the vital role of selenow in rainbow trout muscle response to dietary Se levels and provide a theoretical basis for studies of selenow.

Selenium Status Affects Hypertrophic Growth of Skeletal Muscle in Growing Zebrafish by Mediating Protein Turnover.

BACKGROUND: Selenium (Se) status is closely related to skeletal muscle physiological status. However, its influence on skeletal muscle growth has not been well studied. OBJECTIVES: This study aimed to analyze the impacts of overall Se status (deficient, adequate, and high) on skeletal muscle growth using a growing zebrafish model. METHODS: Zebrafish (1.5-mo-old) were fed graded levels of Se (deficient: 0.10 mg Se/kg; marginally deficient: 0.22 mg Se/kg; adequate: 0.34 mg Se/kg; high: 0.44, 0.57, and 0.69 mg Se/kg) as Se-enriched yeast for 30 d. Zebrafish growth, and Se accumulation, selenoenzyme activity, selenotranscriptome profiles, and oxidative status in the whole body, and selenotranscriptome profiles, histological characteristics, biochemicals, and gene and protein expression profiles related to muscle growth in the skeletal muscle were analyzed by model fitting and/or 1-factor ANOVA. RESULTS: Se status biomarkers within the whole body and skeletal muscle indicated that 0.34 mg Se/kg was adequate for growing zebrafish. For biomarkers related to skeletal muscle growth, compared with 0.34 mg Se/kg, 0.10 mg Se/kg decreased the white muscle cross-sectional area (WMCSA) and the mean diameter of white muscle fibers (MDWMF) by 14.4%-15.1%, inhibited protein kinase B-target of rapamycin complex 1 signaling by 63.7%-68.5%, and stimulated the autophagy-lysosome pathway by 1.07 times and the ubiquitin-proteasome pathway (UPP) by 96.0% (P < 0.05), whereas 0.22 mg Se/kg only decreased the WMCSA by 7.8% (P < 0.05); furthermore, 0.44 mg Se/kg had no clear effects on skeletal muscle biomarkers, whereas 0.57-0.69 mg Se/kg decreased the WMCSA and MDWMF by 6.3%-25.9% and 5.1%-21.3%, respectively, and stimulated the UPP by 2.23 times (P < 0.05). CONCLUSIONS: A level of 0.34 mg Se/kg is adequate for the growth of zebrafish skeletal muscle, whereas ≤0.10 and ≥0.57 mg Se/kg are too low or too high, respectively, for maintaining efficient protein accretion and normal hypertrophic growth.

Effect of dietary selenium on postprandial protein deposition in the muscle of juvenile rainbow trout (Oncorhynchus mykiss).

Se, an essential biological trace element, is required for fish growth. However, the underlying mechanisms remain unclear. Protein deposition in muscle is an important determinant for fish growth. This study was conducted on juvenile rainbow trout (Oncorhynchus mykiss) to explore the nutritional effects of Se on protein deposition in fish muscle by analysing the postprandial dynamics of both protein synthesis and protein degradation. Trout were fed a basal diet supplemented with or without 4 mg/kg Se (as Se yeast), which has been previously demonstrated as the optimal supplemental level for rainbow trout growth. After 6 weeks of feeding, dietary Se supplementation exerted no influence on fish feed intake, whereas it increased fish growth rate, feed efficiency, protein retention rate and muscle protein content. Results of postprandial dynamics (within 24 h after feeding) of protein synthesis and degradation in trout muscle showed that dietary Se supplementation led to a persistently hyperactivated target of rapamycin complex 1 pathway and the suppressive expression of numerous genes related to the ubiquitin-proteasome system and the autophagy-lysosome system after the feeding. However, the ubiquitinated proteins and microtubule-associated light chain 3B (LC3)-II:LC3-I ratio, biomarkers for ubiquitination and autophagy activities, respectively, exhibited no significant differences among the fish fed different experimental diets throughout the whole postprandial period. Overall, this study demonstrated a promoting effect of nutritional level of dietary Se on protein deposition in fish muscle by accelerating postprandial protein synthesis. These results provide important insights about the regulatory role of dietary Se in fish growth.

Synthesis, Structures, and Fluorescence Properties of Dimeric Aluminum Oxo Clusters.

Aluminum is an important component for luminescence. However, the fluorescent aluminum complex with unambiguous structural information is still limited. Herein, we report a series of fluorescence aluminum oxo clusters (AlOCs). By introducing an additional coordination site to the aromatic conjugation ligand, cluster nuclearity increment and fluorescence variation are observed. Al8(OH)2(µ4-O)2(1-NA)2(OEt)16 (AlOC-41, 1-NA = 1-naphthoic acid, OEt = ethanol) is made up of two tetrahedral subunits. By introducing an additional coordination site to the aromatic conjugation ligand, we isolate a high nuclearity compound Al10(µ3-O)2(3-HNA)2(OEt)22 (AlOC-47, 3-HNA = 3-hydroxy-2-naphthoic acid). Correspondingly, their luminescence performance is different (blue fluorescence in AlOC-41 and green in AlOC-47). Present herein is a platform to illustrate the relationship between synthesis, structure, and fluorescence properties.

Analysis of influence factors of pharmacodynamics of propofol with target-controlled infusion during anesthetic recovery period.

OBJECTIVE: To explore the pharmacodynamic (PD) characteristics of propofol during anesthetic recovery period with target-controlled infusion (TCI), and to identify the clinical variables related to the PD parameters. MATERIALS AND METHODS: 20 patients scheduled for otolaryngology surgery were enrolled. After the surgery was finished, target effect site concentration was gradually decreased, blood samples were measured at 7 time points and the differences between the target and measured plasma concentration were compared. Observer's assessment of alertness/sedation (OAA/S) and Narcotrend index (NI) were used as two PD indicators by fitting sigmoid Emax model. Correlations between PD parameter and clinical variables were evaluated. RESULTS: Performance of the TCI system showed a positive bias at the end of the anesthesia sedation period and a negative bias in the anesthetic recovery period. PD parameters (EC50, r) calculated with OAA/S and NI were significantly different, EC50 of OAA/S was lower than EC50 of NI (1.53 ± 0.70 vs. 2.16 ± 0.99 µg/mL), r of OAA/S was higher than r of NI (57.07 ± 56.39 vs. 4.35 ± 4.42). Propofol dosage and hemodynamic parameters were significantly correlated with EC50 (OAA/S), lean body weight and gender were significantly correlated with EC50 (NI). CONCLUSION: NI provided a more stable and adequate assessment of the depth of anesthesia than OAA/S, and the influence factors should be taken into account for precise dosing.

Designable Al32 -Oxo Clusters with Hydrotalcite-like Structures: Snapshots of Boundary Hydrolysis and Optical Limiting.

The hydrolysis of earth-abundant AlIII has implications in mineral mimicry, geochemistry and environmental chemistry. Third-order nonlinear optical (NLO) materials are important in modern chemistry due to their extensive optical applications. The assembly of AlIII ions with π-conjugated carboxylate ligands is carried out and the hydrolysis and NLO properties of the resultant material are studied. A series of Al32 -oxo clusters with hydrotalcite-like cores and π-conjugated shells are isolated. X-ray diffraction revealed boundary hydrolysis occurs at the equatorially unsaturated coordination sites of AlIII ions. Charge distribution analysis and DFT calculations support the proposed boundary substitution. The Al32 -oxo clusters possess a significant reverse saturable absorption (RSA) response with a minimal normalized transmittance up to 29 %, indicating they are suitable candidates for optical limiting (OL) materials. This work elucidates the hydrolysis of AlIII and provides insight into layered materials that also have strong boundary activity at the edges or corners.

Potential Human Health Risks of Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) Associated with Fish Consumption in Anhui Province, China.

In this study, the concentrations of 14 types of organochlorine pesticides (OCPs) and 7 types of polychlorinated biphenyls (PCBs) in four freshwater fish species (Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix and Hypophthalmichthys nobilis) collected from nine lakes in Anhui Province were determined. Among these contaminants, only hexachlorobenzene (HCB), heptachlor, hexachlorocyclohexane (ß- and γ-HCH), dichlorodiphenyldichloroethylene (p,p'-DDE) and PCB 101 were detected, and HCB had the highest measured concentrations while the heptachlor showed the lowest concentrations. In the four fish species, C. carpio preferred to accumulate more OCPs and PCBs than C. idellus. Moreover, the health risk assessments demonstrated that consumption of these fish species may pose both non-carcinogenic and carcinogenic risks, especially for children at high exposure level (95th). As the concentrations of contaminants in ventral muscle were higher than that in dorsal muscle, the consumption of ventral muscle should be limited to avoid the potential risk of OCPs and PCBs.

Silence of cytoskeleton-associated protein 2 represses cell proliferation and migration and promotes apoptosis in liver cancer cell lines. / æ²‰é»˜ç»†èƒžéª¨æž¶ç›¸å ³è›‹ç™½2抑制肝癌细胞增殖和迁移并促进细胞凋亡.

OBJECTIVES: To investigate the roles of cytoskeleton-associated protein 2 (CKAP2) in proliferation, apoptosis, and migration in liver cancer cells and the potential mechanisms. METHODS: Human normal hepatocyte L02 and liver cancer cell lines HepG2, Huh7, and SMMC-7721 were cultured. The CKAP2 expression was detected by real-time PCR and Western blotting. HepG2 cells were randomly divided into a control group, a negative control (NC) group, and a CKAP2 silencing (siCKAP2) group. CCK-8 and BrdU assays were used to evaluate cell viability and proliferation, respectively. Transwell assay was employed to determine cell migration and invasion. The protein levels of cleaved-caspase 3, Bax, E-cadherin, N-cadherin, Vimentin, phosphorylated Janus kinase 2 (p-JAK2), and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) were determined by Western blotting. RESULTS: Compared with normal hepatocyte L02, CKAP2 was highly expressed in liver cancer cell lines HepG2, Huh7, and SMMC-7721 (all P<0.05). Compared with the NC group, cell viability and proliferation rate of the siCKAP2 group were decreased (both P<0.05). The apoptotic rate, protein expression of cleaved-caspase 3 and Bax in the siCKAP2 group were significantly higher than those in the NC group (all P<0.05). Compared with the NC group, cell migration and invasion rates of the siCKAP2 group were significantly attenuated (both P<0.05). Compared with the NC group, E-cadherin protein expression in siCKAP2 group was increased, while protein expression levels of Vimentin, N-cadherin, p-JAK2, and p-STAT3 were decreased (all P<0.05). CONCLUSIONS: CKAP2 gene silence inhibits proliferation, migration, and invasion, and promotes apoptosis in liver cancer cells, while JAK2/STAT3 signaling pathway may be involved in these processes.

Multiscale Time-Sharing Elastography Algorithms and Transfer Learning of Clinicopathological Features of Uterine Cervical Cancer for Medical Intelligent Computing System.

Intelligent medical diagnosis and computing system faces many challenges in complex object recognition, large-scale data imaging and real-time diagnosis, such as poor real-time computing, low efficiency of data storage and low recognition rate of lesions. In order to solve the above problems, this paper proposes a medical intelligent computing system and a series of algorithms for the clinical pathology of cervical cancer based on the multi-scale imaging and transfer learning framework. Firstly, based on data dimensions, imaging errors and other factors, this paper designs a multi-scale time-sharing elastic imaging algorithm based on image reconstruction time and data sample characteristics. Then, taking the burst imaging cohort and the calculation data set of new cervical cancer cases as the objects, based on the difficulties of cervical cancer feature modeling, this paper proposes the transfer learning algorithm of clinical and pathological features of cervical cancer. Finally, a medical intelligent computing system for cervical cancer pathology analysis and calculation with high efficiency and reliability is established. A series of proposed algorithms are compared with single-scale Retinex (SSR), which is based on single-scale Retinex migration learning (SSR-TL). The experimental results show that the proposed algorithm in cervical cancer pathological imaging and scoring, as well as the feature extraction and recognition of lesions, especially the efficiency of system execution, is obviously due to the comparison algorithm.

Explorations of the optimal method for isolating oocytes from zebrafish (Danio rerio) ovary.

Obtaining oocytes from the adult female zebrafish (Danio rerio) ovary has enormous importance in the studies of developmental biology, toxicology, and genetics. It is vital to establish a simple and effective approach to ensure the quantity and quality of oocytes, which will enable the success of follow-up experimental investigation finally. Usually, oocytes are separated with mechanical or enzymatic methods, however, little studies have been done with concerns about the comparative effects. The present study separated zebrafish oocytes of Stage III with five frequently used methods, including stripping, pipetting, hyaluronidase (1.6 mg/ml), collagenase (0.4 mg/ml), and trypsin (0.1%). The cell viability, oxidative stress, mitogen-activated protein kinase (MAPK) protein phosphorylation, and apoptosis levels were selected as main biomarkers to evaluate the oocytes health status. The results showed that both trypsin and hyaluronidase isolation significantly upregulated germinal vesicle breakdown (GVBD) rates and downregulated p38 MAPK activity simultaneously. GVBD rates and survival rates were decreased notably in oocytes separated by the collagenase method. Above results indicate that zebrafish oocytes in vitro are sensitive to enzymatic treatments and the enzymatic isolation is not the suitable mean for collecting zebrafish oocytes although it is time-saving. The mechanical strategy of pipetting remarkably increased the reactive oxygen species and malondialdehyde level in isolated oocytes. Interestingly, oocytes separated with stripping show less physiological and biochemical damages. Therefore, stripping isolation is comparatively recommended as the optimum method for separating and collecting numerous intact and healthy zebrafish oocytes in vitro for the subsequent developmental research.

Effects of dietary toxic cyanobacteria and ammonia exposure on immune function of blunt snout bream (Megalabrama amblycephala).

Cyanobacterial blooms caused by water eutrophication have become a worldwide problem. During the degradation of toxic cyanobacterial blooms, elevated ammonia and microcystins concentrations co-occur and exert toxicity on fish. Up to now, the combined effect of microcystins and ammonia on fish immunotoxicity has not been reported. The present study investigated immune responses of blunt snout bream (Megalabrama amblycephala) to dietary toxic cyanobacteria and ammonia exposure. Megalobrama amblycephala were exposed to solutions with different concentrations of NH3-N (0, 0.06, 0.12 mg/L) and fed with diets containing 15% and 30% of toxic cyanobacteria lyophilized powder for 30 d. The microcystins concentration in different organs of Megalobrama amblycephala was in the following sequence: head kidney > liver > intestine > gonad > spleen > gill > trunk kidney > brain > muscle > heart. In both head kidney and spleen, the MC-LR and MC-RR concentration increased significantly with increasing NH3-N concentration. It indicates that NH3-N maybe promote the accumulation of microcystins in immune organs of Megalobrama amblycephala. Meanwhile, broadened peripheral interspace of lymphocytes, nucleus shrivel and edematous mitochondria were observed in head kidney lymphocyte of toxic treatment fish. Moreover, there were significant interactions between dietary toxic cyanobacteria and ammonia exposure on head kidney macrophage phagocytosis activity, respiratory burst activities, total number of white blood cells and the transcriptional levels of sIgM, mIgD and sIgZ genes. Our data clearly demonstrated that dietary toxic cyanobacteria combined with ammonia exposure showed a synergistic effect on Megalobrama amblycephala immunotoxicity.

Effects of toxic cyanobacteria and ammonia on flesh quality of blunt snout bream (Megalobrama amblycephala).

BACKGROUND: Toxic cyanobacterial blooms result in the production of an organic biomass containing cyanotoxins (e.g. microcystins) and an elevated ammonia concentration in the water environment. The ingestion of toxic cyanobacteria and exposure to ammonia are grave hazards for fish. The present study assessed the effects of dietary toxic cyanobacteria and ammonia exposure on the flesh quality of blunt snout bream (Megalobrama amblycephala). RESULTS: Dietary toxic cyanobacteria and ammonia exposure had no impact on fish growth performance, fillet proximate composition and drip loss, whereas it significantly decreased fillet total amino acids, total essential amino acids, hardness and gumminess, and increased fillet ultimate pH as well as malondialdehyde content. However, there was no significant interaction between dietary toxic cyanobacteria and ammonia exposure on these parameters. Additionally, dietary toxic cyanobacteria significantly increased fillet initial pH, thaw loss and protein carbonyl content, whereas ammonia exposure did not. CONCLUSION: The results of the present study indicate that dietary toxic cyanobacteria and ammonia exposure reduced the quality of blunt snout bream fillet. © 2016 Society of Chemical Industry.

De Novo Glutamine Synthesis: Importance for the Proliferation of Glioma Cells and Potentials for Its Detection With 13N-Ammonia.

PURPOSE: The aim of this study was to investigate the role of de novo glutamine (Gln) synthesis in the proliferation of C6 glioma cells and its detection with (13)N-ammonia. METHODS: Chronic Gln-deprived C6 glioma (0.06C6) cells were established. The proliferation rates of C6 and 0.06C6 cells were measured under the conditions of Gln deprivation along with or without the addition of ammonia or glutamine synthetase (GS) inhibitor. (13)N-ammonia uptake was assessed in C6 cells by gamma counting and in rats with C6 and 0.06C6 xenografts by micro-positron emission tomography (PET) scanning. The expression of GS in C6 cells and xenografts was assessed by Western blotting and immunohistochemistry, respectively. RESULTS: The Gln-deprived C6 cells showed decreased proliferation ability but had a significant increase in GS expression. Furthermore, we found that low concentration of ammonia was sufficient to maintain the proliferation of Gln-deprived C6 cells, and (13)N-ammonia uptake in C6 cells showed Gln-dependent decrease, whereas inhibition of GS markedly reduced the proliferation of C6 cells as well as the uptake of (13)N-ammoina. Additionally, microPET/computed tomography exhibited that subcutaneous 0.06C6 xenografts had higher (13)N-ammonia uptake and GS expression in contrast to C6 xenografts. CONCLUSION: De novo Gln synthesis through ammonia-glutamate reaction plays an important role in the proliferation of C6 cells. (13)N-ammonia can be a potential metabolic PET tracer for Gln-dependent tumors.

Dietary microbial phytase exerts mixed effects on the gut health of tilapia: a possible reason for the null effect on growth promotion.

The present study evaluated the effects of dietary microbial phytase on the growth and gut health of hybrid tilapia (Oreochromis niloticus ♀×Oreochromis aureus ♂), focusing on the effect on intestinal histology, adhesive microbiota and expression of immune-related cytokine genes. Tilapia were fed either control diet or diet supplemented with microbial phytase (1000 U/kg). Each diet was randomly assigned to four groups of fish reared in cages (3×3×2 m). After 12 weeks of feeding, weight gain and feed conversion ratio of tilapia were not significantly improved by dietary microbial phytase supplementation. However, significantly higher level of P content in the scales, tighter and more regular intestinal mucosa folds were observed in the microbial phytase group and the microvilli density was significantly increased. The adhesive gut bacterial communities were strikingly altered by microbial phytase supplementation (0·41

sIgZ exhibited maternal transmission in embryonic development and played a prominent role in mucosal immune response of Megalabrama amblycephala.

IgZ is considered to be the last immunoglobulin discovered in vertebrate species. In this study, the structure of secreted form of blunt snout bream (Megalabrama amblycephala) IgZ (sIgZ) heavy chain gene is VH-Cζ1-Cζ2-Cζ3-Cζ4, in which Cζ4 provides the specificity to the IgZ isotype. The deduced amino acid sequence of sIgZ shows highest similarity with that of Ctenopharyngodon idella (79%). The ontogeny of sIgZ gene expression showed a V-shape change pattern: decreased initially from unfertilized egg stage to 16-cell embryos and increased significantly from blastula stage, which exhibited maternal transmission effects. Compared with the juvenile fish, sIgZ mRNA level was higher in head kidney, spleen, trunk kidney, liver, intestine and gill of adult fish. In both juvenile and adult fish, sIgZ mRNA was detected in intestine and gill. Aeromonas hydrophila challenge experiment showed that sIgZ transcription significantly increased in skin, gill and intestine, indicating a prominent mucosal immune response. The results of Western blot also verified the protein alterations of sIgZ in mucosal organs in M. amblycephal. Our studies indicate a prominent role of IgZ in mucosa-associated lymphoid tissue immunity and further support the specialized role of IgZ in teleost mucosal immune responses.

Population-specific plasma proteomes of marine and freshwater three-spined sticklebacks (Gasterosteus aculeatus).

Molecular phenotypes that distinguish resident marine (Bodega Harbor) from landlocked freshwater (FW, Lake Solano) three-spined sticklebacks were revealed by label-free quantitative proteomics. Secreted plasma proteins involved in lipid transport, blood coagulation, proteolysis, plasminogen-activating cascades, extracellular stimulus responses, and immunity are most abundant in this species. Globulins and albumins are much less abundant than in mammalian plasma. Unbiased quantitative proteome profiling identified 45 highly population-specific plasma proteins. Population-specific abundance differences were validated by targeted proteomics based on data-independent acquisition. Gene ontology enrichment analyses and known functions of population-specific plasma proteins indicate enrichment of processes controlling cell adhesion, tissue remodeling, proteolytic processing, and defense signaling in marine sticklebacks. Moreover, fetuin B and leukocyte cell derived chemotaxin 2 are much more abundant in marine fish. These proteins promote bone morphogenesis and likely contribute to population-specific body armor differences. Plasma proteins enriched in FW fish promote translation, heme biosynthesis, and lipid transport, suggesting a greater presence of plasma microparticles. Many prominent population-specific plasma proteins (e.g. apoptosis-associated speck-like protein containing a CARD) lack any homolog of known function or adequate functional characterization. Their functional characterization and the identification of population-specific environmental contexts and selective pressures that cause plasma proteome diversification are future directions emerging from this study.

Spatio-temporal expression of blunt snout bream (Megalobrama amblycephala) mIgD and its immune response to Aeromonas hydrophila.

The function of IgD in fish and mammals has not been fully understood since its discovery. In this study, we have isolated and characterized the cDNA that encodes membrane-bound form of the immunoglobulin D heavy chain gene (mIgD) of blunt snout bream (Megalobrama amblycephala) using RT-PCR and rapid amplification of cDNA ends (RACE). The full-length cDNA of mIgD consisted of 3313 bp, encoding a putative protein of 943 amino acids. The structure of blunt snout bream mIgD is VDJ-µ1-δ1-δ2-δ3-δ4-δ5-δ6-δ7-TM. Multiple alignment and phylogenetic analyses indicated that blunt snout bream mIgD clusters with the homologues of cyprinid fish and that its highest identity is with that of C. idella (82%). The mIgD expression in early different developmental stages showed that the level of mIgD mRNA decreased dramatically from the unfertilized egg stage to the 32-cell stage, suggesting that mIgD mRNA was maternally transferred. As cell differentiation initially took place in the blastula stage, the mIgD expression increased significantly from the blastula stage to prelarva, which might be attributed to embryonic stem cell differentiation processes. Compared with juvenile fish, the expression and tissue distribution patterns of mIgD in adult individuals exhibited considerable variation. After the injection of Aeromonas hydrophila, mIgD expression was up-regulated in various tissues, reaching the peak expression at 5 d, 14 d or 21 d (depending on the tissue type). The present study provides a theoretical basis for further research of the teleost immune system.