Fish appear to harbour a complex type I IFN repertoire containing subgroups a, b, c, d, e, f, and h, and IFNh is only reported in perciform fishes. However, no multiple copies of IFNh gene has been identified in fish to date. In this study, two IFNh genes named On-IFNh1 and On-IFNh2 were cloned from Nile tilapia, Oreochromis niloticus. The predicted proteins of On-IFNh1 and On-IFNh2 contain several structural features known in type I IFNs, and estimation of divergence time revealed that these two genes may have arisen from a much recent local duplication event. On-IFNh genes were constitutively expressed in all tissues examined, with the highest expression level observed in gill, and were rapidly induced in all organs/tissues tested following the stimulation of poly(I:C). In addition, both recombinant On-IFNh1 and On-IFNh2 trigger a relative delayed but sustained induction of interferon-stimulated genes (ISGs), whereas recombinant On-IFNc elicits a rapid and transient expression of ISGs in vivo. The present study thus contributes to a better understanding of the functional properties of tilapia interferons, and also provides a new insight into the evolution of IFNh in fish.

鱼似乎具有包含亚群a，b，c，d，e，f和h的复杂的I型IFN种类，仅在pericform鱼中报告了IFNh。但是，迄今为止，在鱼类中尚未鉴定出IFNh基因的多个拷贝。在这项研究中，从尼罗罗非鱼，尼罗罗非鱼（Oreochromis niloticus）克隆了两个名为On-IFNh1和On-IFNh2的IFNh基因。。On-IFNh1和On-IFNh2的预测蛋白包含I型IFN中已知的几个结构特征，并且对发散时间的估计表明这两个基因可能是由于最近的局部复制事件引起的。On-IFNh基因在所有检查的组织中组成性表达，在g中观察到最高的表达水平，并在刺激poly（I：C）后在所有测试的器官/组织中迅速诱导。此外，重组On-IFNh1和On-IFNh2均会触发相对延迟但持续的干扰素刺激基因（ISG）诱导，而重组On-IFNc则在体内迅速且短暂地表达ISG 。。因此，本研究有助于更好地了解罗非鱼干扰素的功能特性，并为鱼类中IFNh的进化提供新见解。