Behavioural fever in zebrafish larvae.
Behavioural fever has been reported in different species of mobile ectotherms including the zebrafish, Danio rerio, in response to exogenous pyrogens. In this study we report, to our knowledge for the first time, upon the ontogenic onset of behavioural fever in zebrafish (Danio rerio) larvae. For this, zebrafish larvae (from first feeding to juveniles) were placed in a continuous thermal gradient providing the opportunity to select their preferred temperature. The novel thermal preference aquarium was based upon a continuous vertical column system and allows for non-invasive observation of larvae vertical distribution under isothermal (TRat 28 °C) and thermal gradient conditions (TCH: 28-32 °C). Larval thermal preference was assessed under both conditions with or without an immersion challenge, in order to detect the onset of the behavioural fever response. Our results defined the onset of the dsRNA induced behavioural fever at 18-20 days post fertilization (dpf). Significant differences were observed in dsRNA challenged larvae, which prefer higher temperatures (1-4 °C increase) throughout the experimental period as compared to non-challenged larvae. In parallel we measured the abundance of antiviral transcripts; viperin, gig2, irf7, trim25 and Mxb mRNAs in dsRNA challenged larvae under both thermal regimes: TRand TCh. Significant increases in the abundance of all measured transcripts were recorded under thermal choice conditions signifying that thermo-coupling and the resultant enhancement of the immune response to dsRNA challenge occurs from 18 dpf onwards in the zebrafish. The results are of importance as they identify a key developmental stage where the neuro-immune interface matures in the zebrafish likely providing increased resistance to viral infection.
Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, 08193 Bellaterra, Spain.
Sonia
S
Rey
Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, 08193 Bellaterra, Spain.
Visila
V
Moiche
Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, 08193 Bellaterra, Spain.
Sebastian
S
Boltaña
Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, 08193 Bellaterra, Spain.
Mariana
M
Teles
Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, 08193 Bellaterra, Spain. Electronic address: Simon.MacKenzie@stir.ac.uk.
Simon
S
MacKenzie
D000818:Animals; D002478:Cells, Cultured; D005334:Fever / Q000276:immunology*; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006358:Hot Temperature; D007113:Immunity, Innate / Q000235:genetics; D050835:Interferon Regulatory Factors / Q000235:genetics / Q000378:metabolism; D007814:Larva; D015213:Neuroimmunomodulation; D011506:Proteins / Q000235:genetics; D011749:Pyrogens / Q000276:immunology; D012330:RNA, Double-Stranded / Q000276:immunology; D050821:Transcription Factor Brn-3C / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish / Q000502:physiology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism; D000090123:Viperin Protein
D018398:Homeodomain Proteins; D050835:Interferon Regulatory Factors; D011506:Proteins; D011749:Pyrogens; D012330:RNA, Double-Stranded; D050821:Transcription Factor Brn-3C; D014157:Transcription Factors; D029961:Zebrafish Proteins; C555118:IRF7 protein, zebrafish; C417529:Rsad2 protein, mouse; D000090123:Viperin Protein; C574009:gig2i protein, zebrafish
Antiviral response; Behavioural fever; Larval development; Temperature choice; Thermo-preference; Zebrafish larvae; dsRNA challenge