Identification and functional characterization of a circular RNA circeIF4G3: a negative regulator of innate immunity...

In recent years, the unique circular structure of circular RNAs (circRNAs) has been the focus of much attention and research. RNA molecules without coding function weave a complex regulatory network in mammals, affecting the progress of many biological processes. This discovery opens up a new perspective on the function of the genome. However, the powerful regulatory functions of circular RNAs in fish are still unclear. We identified a novel circular RNA, dubbing it circeIF4G3. Through qPCR and dual luciferase assays, we found that circeIF4G3 reduces the production of antiviral genes and inflammatory factors. We discovered that circeIF4G3 both hindered cell proliferation and diminished cell viability concurrently. These results suggest that circeIF4G3 is not only involved in the innate immunity of miiuy croaker, but also plays an inhibitory role in it. This discovery provides a new research approach for a deeper understanding of the immune regulatory mechanism of miiuy croaker. This study enriches the non-coding RNAs regulatory network in innate immunity in teleost fish, and establishes a foundation for investigating the role of circular RNAs in teleost fish's innate immunity.