Fig. 1
From: Deep Insights in Circular RNAs: from biogenesis to therapeutics
Models of circular Biogenesis a) Lariat-driven circularization or exon skipping model. Splice donor in 3′ end of Exon 1 covalently splices to splice acceptor in 5′ end of Exon 4 forms a lariat through Exon skipping. The Introns are removed through spliceosome to generate circular RNA. b) Intron-pairing driven circularization or direct back splicing model. Consecutive introns form a circular structure via base pairing. Introns are removed are reatained to form exonic circRNA or EIcircRNA