Arctic charr brain transcriptome strongly affected by summer seasonal growth but only subtly by feed deprivation

• Published in: BMC Genomics
• Main Authors: Striberny, Anja, Jørgensen, Even, Klopp, Christophe, Magnanou, Elodie
• Other Authors: The Arctic University of Norway (UiT), Unité de Biométrie et Intelligence Artificielle de Toulouse Castanet-Tolosan (UBIA), Institut National de la Recherche Agronomique (INRA)-Plateforme bioinformatique du GIS GENOTOUL - Génopole Toulouse Midi-Pyrénées, Biologie intégrative des organismes marins (BIOM), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), UiT - The Arctic University of Tromso, French Ministries of Europe and Foreign affairs (Ministere de l'Europe et des Affaires etrangeres - MEAE), higher education, research and innovation (Ministere de l'Enseignement superieur, de la Recherche et de l'Innovation - MESRI), Aurora mobility programme - researcher exchange, UiT - The Arctic University of Norway
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Neuropeptides; Season; Feed deprivation; Salvelinus alpinus; RNA-seq; Brain transcriptome; [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry; Molecular Biology/Genomics [q-bio.GN]; Arctic; Arctic charr
• Online Access: https://hal.sorbonne-universite.fr/hal-02182476; https://hal.sorbonne-universite.fr/hal-02182476/document; https://hal.sorbonne-universite.fr/hal-02182476/file/document.pdf; https://doi.org/10.1186/s12864-019-5874-z

International audience BackgroundThe Arctic charr (Salvelinus alpinus) has a highly seasonal feeding cycle that comprises long periods of voluntary fasting and a short but intense feeding period during summer. Therefore, the charr represents an interesting species for studying appetite-regulating mechanisms in fish.ResultsIn this study, we compared the brain transcriptomes of fed and feed deprived charr over a 4 weeks trial during their summer feeding season. Despite prominent differences in body condition between fed and feed deprived charr at the end of the trial, feed deprivation affected the brain transcriptome only slightly. In contrast, the transcriptome differed markedly over time in both fed and feed deprived charr, indicating strong shifts in basic cell metabolic processes possibly due to season, growth, temperature, or combinations thereof. The GO enrichment analysis revealed that many biological processes appeared to change in the same direction in both fed and feed deprived fish. In the feed deprived charr processes linked to oxygen transport and apoptosis were down- and up-regulated, respectively. Known genes encoding for appetite regulators did not respond to feed deprivation. Gene expression of Deiodinase 2 (DIO2), an enzyme implicated in the regulation of seasonal processes in mammals, was lower in response to season and feed deprivation. We further found a higher expression of VGF (non-acronymic) in the feed deprived than in the fed fish. This gene encodes for a neuropeptide associated with the control of energy metabolism in mammals, and has not been studied in relation to regulation of appetite and energy homeostasis in fish.ConclusionsIn the Arctic charr, external and endogenous seasonal factors for example the increase in temperature and their circannual growth cycle, respectively, evoke much stronger responses in the brain than 4 weeks feed deprivation. The absence of a central hunger response in feed deprived charr give support for a strong resilience to the lack of food in this high ...