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

► Zebrafish IL-6 was identified using the synteny between human and zebrafish genome. ► The expression of IL-6 and the IL-6 receptor complex, IL-6R and gp130, was studied. ► Their expression was modulated by immunostimulation. ► The genes were expressed at early ages mainly in the head, epidermis and neuromasts.