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: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:In the North Sea and adjacent North Atlantic coastal areas fish experience relatively high levels of persistent organic pollutants. The aim of this study is to compare the mode of actions of environmentally relevant concentrations of halogenated compounds and their mixtures in Atlantic cod. Juvenile male cod were fed mixtures of chlorinated (PCBs, DDT analogs, chlordane, lindane and toxaphene), brominated (PBDEs) and fluorinated (Perfluorooctanesulfonate/PFOS) compounds for one month. One group received a mixture of all three compounds. Transcriptome analysis of liver samples was performed to identify the main affected pathways. Accumulated levels of chemicals in cod liver reflected concentrations found in wild fish. Pathway analysis revealed that the treatment effects by each of the three groups of chemicals (chlorinated, brominated and fluorinated) converged on activation of the unfolded protein response (UPR). The results of our transcriptomics analysis suggest that the UPR pathway is a sensitive common target of halogenated organic environmental pollutants
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.
