Melatonin Inhibits GnRH-1, GnRH-3 and GnRH Receptor Expression in the Brain of the European Sea Bass, Dicentrarchus labrax

Abstract Background: While the stress response inspired genome-wide epigenetic studies in vertebrate models, it remains mostly ignored in fish. We modified the epiGBS (epiGenotyping By sequencing) technique to explore changes in genome-wide cytosine methylation to a repeated acute stress challenge in the nucleated red blood cells (RBCs) of the European sea bass (Dicentrarchus labrax). This species is widely studied in both the natural and farmed environments, including issues regarding health and welfare.Results: We retrieved 501,108,033 sequencing reads after trimming, with a mean mapping efficiency of 73.0% (unique best hits). Minor changes in RBC methylome appear to manifest after the stress challenge. Only, fifty-seven differentially methylated cytosines (DMCs) close to 51 distinct stress-related genes distributed on 17 of 24 linkage groups (LGs) were detected between RBCs of pre- and post-stress individuals. However, literature surveys indicated that 38 of these genes were previously reported as differentially expressed in the brain of zebrafish, most of them involved in stress coping differences. DMC-related genes associated to the Brain Derived Neurotrophic Factor, a protein that favors stress adaptation and fear memory, appear especially relevant to integrate a centrally produced stress response.Conclusion: By putting forward DMCs associated to stress-related genes, we show that minimally invasive RBCs deserve more attention to investigate the epigenetic response to stress and components of the stress response without sacrificing fish. In parallel to blood parameter measurements (e.g. cortisol, glucose levels), and other molecular approaches (e.g. gene expression variation), features of the epigenetic landscape may offer new opportunities for biomonitoring components of the stress response in fish.

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Genome-Wide Epigenomic Stress Response in the European Sea Bass (Dicentrarchus Labrax, L.)

10.21203/rs.3.rs-48905/v1 ◽

2020 ◽

Author(s):

Madoka V. KRICK ◽

Erick DESMARAIS ◽

Athanasios SAMARAS ◽

Elise GUERET ◽

Arkadios DIMITROGLOU ◽

...

Keyword(s):

Stress Response ◽

Cytosine Methylation ◽

Acute Stress ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

European Sea Bass ◽

Nucleated Red Blood Cells ◽

Genome Wide ◽

A Genome ◽

The Brain

Abstract Background: While the stress response inspired genome-wide epigenetic studies in vertebrate models, it remains mostly ignored in fish. We modified the epiGBS (epiGenotyping By sequencing) technique to explore changes in genome-wide cytosine methylation to a repeated acute stress challenge in the nucleated red blood cells (RBCs) of the European sea bass (Dicentrarchus labrax). This species is widely studied in both the natural and farmed environments, including issues regarding health and welfare.Results: We retrieved 501,108,033 sequencing reads after trimming, with a mean mapping efficiency of 73.0% (unique best hits). Fifty-seven differentially methylated cytosines (DMCs) close to 51 distinct stress-related genes distributed on 17 of 24 linkage groups (LGs) were detected between RBCs of pre- and post-stress individuals. Literature surveys indicated that thirty-eight of these genes were previously reported as differentially expressed in the brain of zebrafish, most of them involved in stress coping differences. DMC-related genes associated to the Brain Derived Neurotrophic Factor, a protein that favors stress adaptation and fear memory, are especially relevant.Conclusion: We provide an improved epiGBS protocol with increased multiplexing and sequencing capacities that offer new opportunities to improve data acquisition and to investigate important biological processes at a genome-wide level, such as the stress response. Minimally invasive RBCs deserve more attention to investigate the epigenetic response to stress without sacrificing fish.

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Genome-wide epigenomic stress response in the European sea bass (Dicentrarchus labrax, L.)

10.1101/2020.06.19.160812 ◽

2020 ◽

Author(s):

M.V. Krick ◽

E. Desmarais ◽

A. Samaras ◽

E. Gueret ◽

A. Dimitroglou ◽

...

Keyword(s):

Stress Response ◽

Cytosine Methylation ◽

Acute Stress ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

European Sea Bass ◽

Nucleated Red Blood Cells ◽

Genome Wide ◽

A Genome ◽

The Brain

AbstractBackgroundWhile the stress response inspired genome-wide epigenetic studies in vertebrate models, it remains mostly ignored in fish. We modified the epiGBS (epiGenotyping By sequencing) technique to explore changes in genome-wide cytosine methylation to a repeated acute stress challenge in the nucleated red blood cells (RBCs) of the European sea bass (Dicentrarchus labrax). This species is widely studied in both the natural and farmed environments, including issues regarding health and welfare.ResultsWe retrieved 501,108,033 sequencing reads after trimming, with a mean mapping efficiency of 73.0% (unique best hits). Fifty-seven differentially methylated cytosines (DMCs) close to 51 distinct stress-related genes distributed on 17 of 24 linkage groups (LGs) were detected between RBCs of pre- and post-stress individuals. Literature surveys indicated that thirty-eight of these genes were previously reported as differentially expressed in the brain of zebrafish, most of them involved in stress coping differences. DMC-related genes associated to the Brain Derived Neurotrophic Factor, a protein that favors stress adaptation and fear memory, are especially relevant.ConclusionWe provide an improved epiGBS protocol with increased multiplexing and sequencing capacities that offer new opportunities to improve data acquisition and to investigate important biological processes at a genome-wide level, such as the stress response. Minimally invasive RBCs deserve more attention to investigate the epigenetic response to stress without sacrificing fish.

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CHARACTERIZATION OF THE KISSPEPTIN SYSTEMS IN THE BRAIN OF THE EUROPEAN SEA BASS (Dicentrarchus labrax): RELATIONSHIPS WITH OESTROGEN RECEPTORS

Indian Journal of Science and Technology ◽

10.17485/ijst/2011/v4is.11 ◽

2011 ◽

Vol 4 (s1) ◽

pp. 23-24 ◽

Cited By ~ 1

Author(s):

Escobar S

Keyword(s):

Dicentrarchus Labrax ◽

Sea Bass ◽

Oestrogen Receptors ◽

European Sea Bass ◽

The Brain

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Identification and Regulation of Interleukin-17 (IL-17) Family Ligands in the Teleost Fish European Sea Bass

International Journal of Molecular Sciences ◽

10.3390/ijms21072439 ◽

2020 ◽

Vol 21 (7) ◽

pp. 2439 ◽

Cited By ~ 2

Author(s):

Carmen González-Fernández ◽

Elena Chaves-Pozo ◽

Alberto Cuesta

Keyword(s):

Regulation Of Gene Expression ◽

Dicentrarchus Labrax ◽

Head Kidney ◽

Sea Bass ◽

Interleukin 17 ◽

Target Tissue ◽

Mrna Levels ◽

European Sea Bass ◽

The Brain

Interleukin-17 (IL-17) cytokine comprises a family of six ligands in mammals with proinflammatory functions, having an important role in autoimmune disorders and against bacterial, viral, and fungal pathogens. While IL-17A and IL-17F ligands are mainly produced by Th cells (Th17 cells), the rest of the ligands are expressed by other immune and non-immune cells and have different functions. The identification of IL-17 ligands in fish has revealed the presence of six members, counterparts to mammalian ones, and a teleost-specific form, the fish IL-17N. However, tissue distribution, the regulation of gene expression, and scarce bioactivity assays point to similar functions compared to mammalian ones, though this yet to be investigated and confirmed. Thus, we have identified seven IL-17 ligands in the teleost European sea bass (Dicentrarchus labrax), for the first time, corresponding to IL-17A/F1, IL-17A/F2, IL-17A/F3, IL-17C1, IL-17C2, IL-17D, and IL-17N, according to the predicted protein sequences and phylogenetic analysis. They are constitutively and widely transcribed in sea bass tissues, with some of them being mainly expressed in the thymus, brain or intestine. Upon in vitro stimulation of head-kidney leucocytes, the mRNA levels of all sea bass IL-17 ligands were up-regulated by phytohemagglutinin treatment, a well-known T cell mitogen, suggesting a major expression in T lymphocytes. By contrast, the infection of sea bass juveniles with nodavirus (NNV), a very pathogenic virus for this fish species, resulted in the up-regulation of the transcription of IL-17C1 in the head-kidney and of IL-17C1 and IL-17D in the brain, the target tissue for NNV replication. By contrast, NNV infection led to a down-regulated transcription of IL-17A/F1, IL-17A/F2, IL-17C1, IL-17C2, and IL-17D in the head-kidney and of IL-17A/F1 and IL-17A/F3 in the brain. The data are discussed accordingly with the IL-17 ligand expression and the immune response under the different situations tested.

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