title: mRNA-seq reveals skeletal muscle atrophy in response to handling stress in a marine teleost, the red cusk-eel (Genypterus chilensis).
abstract: BACKGROUND
  Fish reared under intensive conditions are repeatedly exposed to stress, which negatively impacts growth. Although most fish follow a conserved pattern of stress response, with increased concentrations of cortisol, each species presents specificities in the cell response and stress tolerance. Therefore, culturing new species requires a detailed knowledge of these specific responses. The red cusk-eel (Genypterus chilensis) is a new economically important marine species for the Chilean aquaculture industry. However, there is no information on the stress- and cortisol-induced mechanisms that decrease skeletal muscle growth in this teleost.
  
  
  RESULTS
  Using Illumina RNA-seq technology, skeletal muscle sequence reads for G. chilensis were generated under control and handling stress conditions. Reads were mapped onto a reference transcriptome, resulting in the in silico identification of 785 up-regulated and 167 down-regulated transcripts. Gene ontology enrichment analysis revealed a significant up-regulation of catabolic genes associated with skeletal muscle atrophy. These results were validated by RT-qPCR analysis for ten candidates genes involved in ubiquitin-mediated proteolysis, autophagy and skeletal muscle growth. Additionally, using a primary culture of fish skeletal muscle cells, the effect of cortisol was evaluated in relation to red cusk-eel skeletal muscle atrophy.
  
  
  CONCLUSIONS
  The present data demonstrated that handling stress promotes skeletal muscle atrophy in the marine teleost G. chilensis through the expression of components of the ubiquitin-proteasome and autophagy-lysosome systems. Furthermore, cortisol was a powerful inductor of skeletal muscle atrophy in fish myotubes. This study is an important step towards understanding the atrophy system in non-model teleost species and provides novel insights on the cellular and molecular mechanisms that control skeletal muscle growth in early vertebrates.
authors.affiliation: Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Aedo
authors.affiliation: Departamento de Producción Agrícola, Laboratorio de Genómica Funcional & Bioinformática, Universidad de Chile, Facultad de Ciencias Agronómicas, Av. Santa Rosa 11315, La Pintana, 8820808, Santiago, Chile.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Maldonado
authors.affiliation: Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Víctor
authors.initials: V
authors.lastname: Aballai
authors.affiliation: Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Estrada
authors.affiliation: Centro de Biotecnología Vegetal, Facultad Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Macarena
authors.initials: M
authors.lastname: Bastias-Molina
authors.affiliation: Centro de Biotecnología Vegetal, Facultad Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Claudio
authors.initials: C
authors.lastname: Meneses
authors.affiliation: Laboratory of Biotechnology and Aquatic Genomics, Universidad de Concepción, Concepción, Chile.|Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Gallardo-Escarate
authors.affiliation: Departamento de Producción Agrícola, Laboratorio de Genómica Funcional & Bioinformática, Universidad de Chile, Facultad de Ciencias Agronómicas, Av. Santa Rosa 11315, La Pintana, 8820808, Santiago, Chile.
authors.forename: Herman
authors.initials: H
authors.lastname: Silva
authors.affiliation: Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.|Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción, Chile.|Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Molina
authors.affiliation: Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile. jvaldes@unab.cl.|Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción, Chile. jvaldes@unab.cl.|Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile. jvaldes@unab.cl.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Valdés
mesh_terms: D000818:Animals; D019295:Computational Biology / Q000379:methods; D005399:Fishes / Q000235:genetics*; D020869:Gene Expression Profiling; D063990:Gene Ontology; D059014:High-Throughput Nucleotide Sequencing; D006854:Hydrocortisone / Q000494:pharmacology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009133:Muscular Atrophy / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D015203:Reproducibility of Results; D013312:Stress, Physiological / Q000235:genetics*; D059467:Transcriptome
chemical_list: D012333:RNA, Messenger; D006854:Hydrocortisone