Characterisation, expression and ontogeny of interleukin-6 and its receptors in zebrafish (Danio rerio)

Dev Comp Immunol. 2012 May;37(1):97-106. doi: 10.1016/j.dci.2011.11.004. Epub 2011 Nov 15.


Interleukin-6 (IL-6) is one of the most pleiotropic cytokines due to its importance in both innate and adaptive immune responses and other physiological processes. In this study, we identified the zebrafish (Danio rerio) IL-6 homologue by investigating the synteny between the human (Homo sapiens), the fugu (Takifugu rubripes) and the zebrafish genome. Although zebrafish IL-6 showed a low sequence homology with other IL-6 sequences in other species, it presented a high structural similarity to human IL-6. We also analysed IL-6 expression in several different tissues, along with analysis of the expression of the genes that form the IL-6 receptor complex, IL-6R and gp130. After treatment with bacterial or viral stimuli, zebrafish IL-6 expression was modulated in a manner similar to that of other proinflammatory molecules, such as IL-1β and TNF-α. The expression of IL-6, IL-6R and gp130 was also studied during the ontogeny of zebrafish larvae using quantitative PCR and in situ hybridisation. Our results indicated that the transcripts were detected very early, increased during the first week of life and were predominantly expressed in the head, epidermis and neuromasts of the anterior and posterior lateral line system, suggesting their involvement in the normal development of these tissues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Conserved Sequence
  • Cytokine Receptor gp130 / genetics*
  • Cytokine Receptor gp130 / metabolism
  • Gene Expression Regulation, Developmental
  • Gene Order
  • Interferon Inducers / pharmacology
  • Interleukin-6 / chemistry
  • Interleukin-6 / genetics*
  • Interleukin-6 / metabolism
  • Larva / genetics
  • Lipopolysaccharides / pharmacology
  • Molecular Sequence Data
  • Organ Specificity
  • Phylogeny
  • Poly I-C / pharmacology
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Receptors, Interleukin-6 / genetics*
  • Receptors, Interleukin-6 / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Zebrafish / genetics*
  • Zebrafish / immunology
  • Zebrafish Proteins / genetics*
  • Zebrafish Proteins / metabolism


  • Interferon Inducers
  • Interleukin-6
  • Lipopolysaccharides
  • Receptors, Interleukin-6
  • Zebrafish Proteins
  • Cytokine Receptor gp130
  • Poly I-C