In this commentary we briefly summarize early work on circular RNAs derived from spliceosome mediated circularization. We highlight how this early work inspired work on the basic mechanisms of nuclear RNA splicing, the possible function of circular RNAs and the potential uses of circular RNAs as tools in biomedicine. Recent developments in the study of circular RNAs, summarized in this volume, have brought these questions back to the foreground.
Keywords: Circular RNA; Sry; exon circularization; splice site approximation; spliceosome mediated splicing.