Constructing GFP-Based Reporter to Study Back Splicing and Translation of Circular RNA

Human transcriptome contains a large number of circular RNAs (circRNAs) that are mainly produced by back splicing of pre-mRNA. Here we describe a minigene reporter system containing a single exon encoding split GFP in reverse order, which can be efficiently back spliced to produce a circRNA encoding intact GFP gene. This simple reporter system can be adopted to study how different cis-elements and trans-factors affect circRNA production, and also can serve as a reliable system to measure the activity of IRES-mediated translation. Therefore this system can serve as a platform for mechanistic studies on the circRNA biogenesis and its function.