Fig. 1From: The emerging roles and functions of circular RNAs and their generationBack-splicing and canonical splicing of a single pre-mRNA. (a) The single pre-mRNA can be back-spliced with the 5’ terminus of upstream exon 2 ligated to the 3′ terminus of downstream exon 3 to generate a circRNAs. (b) Otherwise, the exons of the pre-mRNA can be joined colinearly by canonical splicing to form mRNAs or lncRNAsBack to article page