Project description:Early life stage mortality is an important issue for Atlantic cod aquaculture. The impact of the cod maternal (egg) transcriptome on egg quality and mortality during embryonic development is poorly understood. In the present work we studied embryonic mortality and maternal transcript expression using 15 females within an Atlantic cod broodstock development program. Cumulative mortality at 7 days post-fertilization (segmentation stage) and percent hatch were used to assess embryonic survival as an indicator of egg quality. A 20,000 probe (20K) microarray experiment compared the 7 hour post-fertilization (7 hpf, ~ 2-cell stage) egg transcriptome of the two lowest quality females (both with less than 1 percent hatch) to that of the highest quality female (greater than 50 percent hatch).
Project description:A stable supply of viable eggs and embryos is crucial for successful farming of Atlantic cod. Broodstock stress can have negative effects, but little is known about the molecular mechanisms that cause abnormal development. Maternally transferred mRNAs have been shown to be essential for normal development, and stress may therefore influence their expression and the subsequent embryonic development. We investigated if mimicked stress in prespawning Atlantic cod females affects mRNA concentrations in eggs and embryos, and if this can be linked to egg/embryo viability, and if we could identify potential molecular markers for stress and egg/embryo viability. Consequently, 3 weeks prior to expected peak spawning, 20 females were intraperitoneally implanted with either cortisol-containing or cortisol-free (sham) osmotic pumps. At peak spawning all individuals were stripped and eggs were fertilized and incubated until hatching. Samples were collected from unfertilized eggs and embryos for gene expression profiling.
Project description:This study was performed to validate the newly developed CGP Atlantic cod 20K oligonucleotide microarray. Atlantic cod (Gadus morhua) received an intraperitoneal injection of either formalin-killed, atypical Aeromonas salmonicida (Asal) or PBS and transcriptional profiles of spleen tissues from Asal-injected fish were compared to those from pre-injection control fish and PBS-injected control fish. Gene expression profiles resulting from this study were compared to those from suppression subtractive hybridization library studies, that were previously performed on the same samples, and to literature. Gene expression patterns of single genes were confirmed by QPCR analysis. This study has shown that the newly developed CGP Atlantic cod 20K oligo microarray platform is a valuable tool for cod genomic research.
Project description:Lipid metabolism is essential in maintaining energy homeostasis in multicellular organisms. In vertebrates, the peroxisome proliferator-activated receptors (PPARs, NR1C) regulate the expression of many genes involved in these processes. Four Ppar subtypes from Atlantic cod (Gadus morhua) were recently cloned and characterized. However, the downstream regulatory role of Ppars in cod lipid metabolism is presently not well understood or described. Here we study the involvement of Atlantic cod Ppar subtypes in systemic regulation of lipid metabolism using the model agonists WY14,643, GW501516, and tetradecylthioacetic acid, employing a multiple omics approach after an in vivo exposure situation.
Project description:This study was conduct to identify the virus-responsive transcripts in Atlantic cod, using viral mimic, polyriboinosinic polyribocytidylic acid (pIC)
Project description:Purpose: The objective of this study is to use Atlantic cod (Gadus morhua) PCLS culture and RNA-seq analysis to map gene expression responses to BaP and EE2 exposure in Atlantic cod. Methods: A total of 8 (3 females and 5 males) juvenile cod (G. morhua) (average body weight 498 g) were used for PCLS (n = 6-8 per group). PCLS preparation and chemical exposure in the culture was performed as previously described (Eide et al., 2014). Cod liver slices were cultured in 24-well plates in the growth medium containing DMSO vehicle (CAS No: 67-68-5), BaP (CAS No: 50-32-8) (10 or 1000 nm), EE2 (CAS No: 57-63-6) (10 or 1000 nm) or BaP and EE2 mixture (10 or 1000 nm each). After 48 hors of culture, the slices were collected and snap frozen in liquid nitrogen and stored at -80 °C for RNA extraction. Results: In total, we had 47 high-quality samples, which were aligned to the published CDS of Atlantic cod (ftp://ftp.ensembl.org/pub/release-90/fasta/gadus_morhua/cds/Gadus_morhua.gad) using HISAT2 v2.1.0 (Kim et al., 2015). Counts were generated from the alignments using SAMtools v1.4.1 (Li et al., 2009). Differential expression analysis was performed using edgeR v3.18.1 (McCarthy et al., 2012) between control group and each treated group using paired test, after removing the genes with all-zero counts across all samples of the two compared groups. Differentially expressed genes were defined by p-value < 0.05 after adjustment using the Benjamini-Hochberg multiple testing correction. Several genes were differentially expressed in the BaP and EE2 and mixture treatment groups compared to the group. Hierarchical clustering showed that signature expression profile of top differentially expressed genes in response to the single treatment was distinctly maintained also in the equimolar binary mixtures. Conclusions: Combining high-throughput RNA-seq analysis and PCLS culture in Atlantic cod, we have shown that BaP and EE2 differentially regulated many genes in the AHR and ER pathways. The results show that omics data can be generated using an efficient PCLS in vitro culture system.
Project description:The Atlantic cod (Gadus morhua L.) is one of the most important species in the Baltic Sea with high ecological and economical value. To explore the differences in adaptation to salinity between Baltic cod from different regions, western (Kiel Bight) and eastern (Gdańsk Bay) samples were analyzed through oligonucleotide microarray.
Project description:The Atlantic cod (Gadus morhua L.) is one of the most important species in the Baltic Sea with high ecological and economical value. To explore the differences in adaptation to salinity between Baltic cod subpopulation: western (Kiel Bight) and eastern (Gdańsk Bay) samples were analyzed through genome-wide oligonucleotide microarray.
Project description:Genome-wide gene expression assay was used to map the genes affected in the liver of Atlantic cod treated with the persistent environmental pollutant polychlorinated biphenyl 153 (PCB 153) (0.5, 2 and 8 mg/kg body weight).