Project description:Groupers (Epinephelidae) are ecologically, commercially, and culturally important predatory fishes throughout their global distribution range in tropical, subtropical and occasionally temperate regions. They are key species for modern and ancient fisheries in the Mediterranean which have been heavily overfished in the past century leading to smaller catch sizes, lower CPUE, and decreased biomass. There are four species of grouper native to the Mediterranean within the Epinephelus genus.The abundance and distribution of grouper species prior to the 20th century in the Mediterranean remains poorly known. Using peptide mass fingerprinting, also known as Zooarchaeology by Mass Spectrometry (ZooMS), we investigated if ZooMS is a viable method for identifying intra-genus grouper bones to species level. Due to the lack of publicly available genomic sequences and for validation of ZooMS markers, we reconstructed collagen type I amino acid sequences using LC-MS/MS for four Epinephelus spp. Adequate variation between collagen sequences enabled the production of the best supported phylogenetic tree for Mediterranean Epinephelus spp. to date. We identified 23 previously undescribed ZooMS biomarkers capable of distinguishing groupers to the species level. Our novel biomarkers were applied to a case study of 23 grouper/comber fish bones from the Middle to Late Holocene archaeological site of Kinet Höyük, located along the coast of Iskenderun Bay, Turkey. ZooMS markers enabled species level identification of 19 bones with 18 identified as Epinephelus aeneus and 1 identified as Epinephelus marginatus. Combining ZooMS identifications with catch size reconstructions has revealed that E. aeneus is capable of growing ca. 30 cm larger than previously reported. This abundance and dominance of E. aeneus locally at Kinet Höyük is consistent with E. aeneus being the most prevalent grouper species in Iskenderun Bay today, testifying to several millennia of this species local population persistence despite fishing pressure, habitat degradation, and climatic changes.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized analysis of the immune response to V. alginolyticus in Epinephelus coioides larvae, we used high-throughput deep sequencing technology to study the effect of infection on gene expression. Methods: Epinephelus coioides larvae (30-days-old) were injected with V. alginolyticus , and fish were sacrificed at 24 h after infection. Ten wild-type Epinephelus coioides larvae were used to build an EST library for transcriptome analysis. The library products were prepared for sequencing analysis using an Illumina HiSeq™ 2000. Raw data were saved as fastq files. The following were removed: reads with adaptors, reads in which over 10% bases were unknown, and low quality reads (i.e., the percentage of bases of quality value ≤ 5 exceeds 50% in the read). Clean reads were mapped to reference sequences using SOAP aligner/soap2 . The randomness of RNA fragmentation was used to construct the library, and the numbers of reads mapped to the reference sequence were calculated. The RPKM method (Reads Per kb per Million reads) was used to calculate gene expression level, and differentially expressed genes (DEGs) Results: A total of 114,851,002 reads were assembled, consisting of 9,687,355,560 nucleotides; these were further assembled into 209,082 contigs with a mean length of 372 bp. Gene ontology (GO) analysis of the transcriptome revealed 12 cellular component subcategories, 16 molecular function subcategories, and 42 biological process subcategories (P value < 0.05). A total of 32664 Epinephelus coioides genes were mapped to the Kyoto Encyclopedia of Genes and Genomes (KEGG); 1504 differentially expressed genes (DEGs) were subsequently identified, in 12 categories (P value < 0.05). Vibrio infection affected the expression of genes involved in complementation, coagulation cascades, pathogen (Staphylococcus aureus) infection, phagosome activity, antigen processing, and the antigen presentation pathway. Conclusions: We conclude that the complement pathway of innate immunity and the hepicidin antimicrobial peptide may play important roles in the defense of Epinephelus coioides larvae against V. alginolyticus, and the immune response may activate at 4h after bacterial infection. These results implicate the complement pathway signal pathway in immunity during V. alginolyticus infection at early developmental stages, enhancing our understanding of the mechanisms underlying the immune response to Vibrio infection in Epinephelus coioides.
Project description:To characterize the site-specific methylation landscape of the Mandarin fish ranavirus (MRV) genome, whole-genome bisulfite sequencing (WGBS) was conducted on an isolated MRV strain.
Project description:E. coioides of the infection group were intrapleurally injected with 105 colony-forming units per fish (cfu/fish) of P. plecoglossicida (wild-type strain or clpV-RNAi strain), while control E. coioides received an equivalent volume of phosphate-buffered saline (PBS). The temperature of the water was maintained at 18 ± 1 °C during the infection experiment. The spleens of E. coioides were collected at 6, 12, 24, 48, 72 and 96 hours post injection (hpi).
Project description:Cortisol was injected into the protogynous epinephelus coioides to investigate the role of this hormone on sex change. Following injection, we evaluated sex-related gene expression during the processes of cortisol-induced sex change in epinephelus coioides.