Publications (94) View all
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Article: Transcriptome Profiling of Gill Tissue in Regionally Bred and Globally Farmed Rainbow Trout Strains Reveals Different Strategies for Coping with Thermal Stress.
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ABSTRACT: Thermal stress can pose a major challenge to salmonid fish. A 4x44K oligonucleotide microarray approach was used to screen for genetically determined variations of a temperature stress response during acclimation in fish gills, a highly specialized and complex organ responsible for gas and electrolyte exchange as well as excretion. The comparison addressed transcriptional changes in the local breeding strain BORN and imported (TCO) rainbow trout after graded 2-week acclimation to 8 and 23 °C. Besides well-characterized mediators of thermoregulation such as genes encoding cold-inducible RNA-binding protein and heat shock proteins, the present microarray study suggests several new candidate genes commonly regulated in gills of the two trout lines. Having identified the differential expression of thermoregulated genes as duplicated paralogues, they were subsequently validated in a gill cell model. Moreover, the comparison of transcriptome profiles provides evidence for distinctively employed expression patterns. The induction of genes encoding factors of the early innate immunity in BORN trout upon warming contrasts with the increased expression of adaptive immune genes in import trout. Cold acclimation induced genes assigned to the functional categories "cell death" and "ion channel activity" in import trout, but repressed "lipid metabolism." This manuscript provides an overview of the genes of the multifunctional gills in rainbow trout that are mandated after temperature change, suggesting links between the different temperature-dependent pathways and gene networks.Marine Biotechnology 04/2013; · 3.43 Impact Factor -
Article: Iron-sulfur cluster scaffold (ISCU) gene is duplicated in salmonid fish and tissue and temperature dependent expressed in rainbow trout.
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ABSTRACT: The iron-sulfur cluster protein ISCU is a scaffold protein tasked with the building and mediation of iron-sulfur [Fe-S]-clusters. These are crucial for [Fe-S]-enzymes, which are involved in essential biological cell processes like metabolism or ion transport. Analysis of ISCU in rainbow trout (Oncorhynchus mykiss) and maraena whitefish (Coregonus maraena) revealed the existence of two gene variants in each of the two salmonids. This study presents the characterization of the duplicated ISCU cDNA sequences in both species as well as the comparative functional analysis of the genes in healthy and affected fish of two rainbow trout strains differing in trait robustness under regional aquaculture conditions. Coding sequences of trout ISCUA and ISCUB genes are spanning over five exons. Open reading frames (ORF) of trout (ISCUA: 495bp, ISCUB: 498bp) and whitefish (ISCUA, ISCUB: 495bp) genes encode for evolutionary highly conserved proteins and share 72% sequence similarity with human ISCU. Transcriptome analyses comparing healthy fish of the local rainbow trout strain BORN and the import strain TCO revealed strain-specific expression patterns for ISCU. Expression analyses by quantitative RT-PCR indicated remarkable differences between the transcript level of the gene variants ISCUA and ISCUB. Moderate temperature challenge (8°C, 23°C) suggests a generally higher transcript level of the two gene variants at 8°C in liver, spleen, and gill of both strains. However, no remarkable differences between the strains occurred in the temperature-dependent ISCU gene expression profiles. The experimental infection with Aeromonas salmonicida resulted in different ISCU gene expression in gill and trunk kidney of both strains after two weeks, suggesting a specific role of the scaffold gene in rainbow trout strain BORN, regarding the recovery after infection. Although results partially reflect the expected strain- and tissue-specific ISCUA and ISCUB regulation in rainbow trout, the data do not support the assumed association of ISCU with the trait robustness.Gene 11/2012; · 2.34 Impact Factor -
Article: Comparison of splenic transcriptome activity of two rainbow trout strains differing in robustness under regional aquaculture conditions.
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ABSTRACT: The spleen plays a crucial role in innate and adaptive immunity in bony fish. Consequently, this organ is well suited to assess the immune competence of an organism and hence provides useful information for comparison and classification of production traits of food fish, such as robustness and susceptibility. To gain information about differences in the basal splenic transcriptome activity, healthy rainbow trout of the commercially important strain TCO and the local selection strain BORN have been compared in a holistic expression analysis using the GRASP 16K cDNA microarray. Nearly all differentially expressed genes (n = 807) in the spleen were on a lower expression level (n = 802) in BORN trout compared to the TCO strain. Global gene ontology analysis revealed that most genes are involved in fundamental biological processes like cellular growth, vesicular trafficking and energy metabolism. Surprisingly, only 7 % of splenic differentially expressed genes are associated with functions of the immune system like TLR signaling, acute phase response and complement system. MARCH3 is one lower expressed gene of interest in BORN trout. This gene, coding for an E3 ubiquitin ligase, is involved in three metabolic functions: immune system, vesicular trafficking and ubiquitination. Since MARCH genes are furthermore differently regulated in the two strains after viral infection and assumed to be potentially active in regulation of immune receptors in fish, MARCH3 was chosen for a closer structural analysis. In concert with the data interpretation of the achieved comparative transcriptome analysis for the involved rainbow trout strains, we provide the full mRNA sequence of trout MARCH3 and its hypothetical protein structure.Molecular Biology Reports 10/2012; · 2.93 Impact Factor -
Article: Tissue-specific mRNA expression patterns reveal a coordinated metabolic response associated with genetic selection for milk production in cows.
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ABSTRACT: The molecular mechanisms regulating the physiological adaptation of tissues important for nutrient partitioning and metabolism in lactating cows are still not completely understood. The aim of our study was to identify tissue-specific regulatory mechanisms necessary to accommodate metabolic changes associated with different genetic potential for milk performance. For this purpose, we analyzed mRNA expression of genes involved in energy metabolism of segregating F(2) beef type cows with a combined genetic dairy and beef background (Charolais × German Holstein cross, CH×GH) in contrast to purebred German Holstein (GH) dairy cows. Three groups of cows differing in milk performance were examined using quantitative real-time PCR in liver, mammary gland, and skeletal muscle. Our results describe substantial tissue-specific differences in mRNA transcription profiles between cow groups in relation to their genetic potential for milk performance and highlight genes exhibiting specific, partially yet-unknown functions in dairy and beef type cows, e.g., upregulation of PCK2 transcripts in the mammary gland and FBP2 transcripts in skeletal muscle of dairy cows. Noticeably, PCCA and PPARGC1A mRNA abundance varied significantly across experimental groups in all three tissues, pointing to potential key gene functions in the metabolic adaptation relative to divergent milk production performance. Correlations of mRNA expression levels to milk performance traits indicate that gene transcriptional processes may play a regulatory role in liver, mammary gland, and skeletal muscle to enable cows with different genetic potential for milk performance to cope with metabolic lactation-associated challenges.Physiological Genomics 06/2012; 44(14):728-39. · 2.73 Impact Factor -
Article: Duplicated NELL2 genes show different expression patterns in two rainbow trout strains after temperature and pathogen challenge.
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ABSTRACT: Mammalian neural epidermal growth factor-like-like 1 and 2 genes (NELL1 and NELL2) encode multifunctional glycoproteins involved in cell growth regulation and differentiation. We isolated two closely related NELL2 transcript sequences from rainbow trout (Oncorhynchus mykiss). These conceptually translated NELL2a and -b sequences share 83% identical residues and the NELL-typical structure. Phylogenetic analyses suggest that bony fish possess two NELL genes, though these are either present as NELL1/2 pair corresponding to their mammalian orthologs or as a NELL2a/2b combination that might have arisen by a fish-specific duplication event. Both trout NELL2 genes are highly expressed at early developmental stages. In adult rainbow trout, NELL2a copies were detected in each tissue analyzed, whereas NELL2b is abundantly expressed only in brain. Cerebral NELL2a/b gene expression seems to be temperature-independent, whereas NELL2a gene expression is clearly down-regulated in gill and up-regulated in muscle tissue after temperature elevation. Infection with Aeromonas salmonicida leads to a considerable increase in NELL2a/b copy number in trunk kidney at day 7 p.i. Moreover, comparative qRT-PCR revealed different NELL2a/b expression pattern in two rainbow trout strains, imported rainbow trout TCO and a local trout selection strain BORN that is known to be resistant to several biotic and abiotic stressors.Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology 05/2012; 163(1):65-73. · 1.61 Impact Factor
