This study focuses in investigating the fatty acid contents of surviving infected hybrid grouper fed with oleic acid immunostimulant. After a 6-week feeding trial, Epinephelus fuscoguttatus × Epinephelus lanceolatus fingerlings were infected with Vibrio vulnificus. One week after bacterial challenge, fish oil was extracted from body tissue of surviving infected fingerlings using the Soxhlet extraction method. The extracted samples were then sent for GC-MS analysis. The raw GC-MS data were analyzed using software programs and databases (i.e., MetaboAnalyst, SIMCA-P, NIST Library, and KEGG). A total of 39 metabolites were putatively identified, with 18 metabolites derived from the fatty acid group. Our further analysis revealed that most metabolites were highly abundant in the oleic acid dietary samples, including oleic acid (4.56%), 5,8,11-eicosatrienoic acid (3.45%), n-hexadecenoic acid (3.34%), cis-erucic acid (2.76%), and 9-octadecenoic acid (2.5%). Worthy of note, we observed a greater abundance of α-linoleic acid (15.57%) in the control diet samples than in the oleic acid diet samples (14.59%) with no significant difference in their results. The results obtained from this study revealed that surviving infected hybrid grouper expressed more immune-related fatty acids due to the effect of oleic acid immunostimulant. Therefore, in this study, we propose oleic acid as a potential immunostimulant in enhancing fish immunity in aquaculture industry.
Matched MeSH terms: Gas Chromatography-Mass Spectrometry/veterinary
In February 2013, forty-seven Notched threadfin bream, the Nemipterus peronii, were sampled from the eastern coastal waters of the South China Sea. The concentration of various elements, namely cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), strontium (Sr), manganese (Mn), selenium (Se), Lead (Pb), nickel (Ni), aluminum (Al), arsenic (As), iron (Fe), and Zinc (Zn) were analyzed in the liver, muscle, and kidney organs of the host, as well as in their parasites Hysterothalycium reliquens (nematode) and the Paraphilometroides nemipteri (nematode), using inductively coupled plasma mass spectrometry (ICP-MS). The former group of parasites showed highest accumulation capacity for Cr, Cu, Fe, Mn, Se, Ni, and Zn while the latter group had high accumulation potential of As, Hg, Cd, Al, Pb, and Sr. The divergence in heavy-metal accumulation profiles of both nematodes is linked with the specificity of microhabitats, cuticle morphology, and interspecific competition. The outcome of this study indicates that both parasite models can be used for biomonitoring of metal pollution in marine ecosystems.
A new proteomics technology has been implemented to study the protein repertoires of developing oocytes of giant grouper (Epinephelus lanceolatus). Knowledge of the chemical composition and physiochemical properties of vitellogenin (Vtg) is necessary to interpret the functional and biological properties attributed during ovulation. Vtg, as a biomarker indicator in sex determination, has been analyzed to determine the sex and maturational status of fish in the absence of the gonad tissue. A male giant grouper was induced by 2 mg/kg of 17ß-estradiol (E2), and blood was sampled at days 0, 1, 3, 5, and 10. SDS-PAGE 1D electrophoresis was used to analyze Vtg protein, and Vtg identification was done with 4800 Plus MALDI TOF/TOF™ mass spectrophotometer (Applied Biosystems/MDS SCIEX, USA). Meanwhile, MS/MS de novo sequencing identified the proteins by matching sequences of tryptic peptides to the known sequences of other species. Vtg was confirmed by MASCOT at 95% significant level, and molecular mass was 187 kDa. Protein resolved on SDS-PAGE as a double band of approximately the same mass as determined with MALDI-TOF. The N-terminal sequences and identification of Vtg were also determined. The potential of using MS methods to understand the structure and function of Vtg is discussed.
Matched MeSH terms: Tandem Mass Spectrometry/veterinary