Sanford and Carter's Genetic Entropy Revisited

[Art (Arthur Hunt)]

@stcordova

It’s not always thrown away:

Exon-intron Circular RNAs Regulate Transcription in the Nucleus - PubMed

A vast number of circular RNAs (circRNAs) have been identified, and some have been shown to function as microRNA sponges in animal cells. Here, we report a class of circRNAs associated with RNA polymerase II in human cells. In these circRNAs, exons are circularized with introns ‘retained’ between exons; we term them exon-intron circRNAs or EIciRNAs. EIciRNAs predominantly localize in the nucleus, interact with U1 snRNP and promote transcription of their parental genes. Our findings reveal a new role for circRNAs in regulating gene expression in the nucleus, in which EIciRNAs enhance the expression of their parental genes in cis, and highlight a regulatory strategy for transcriptional control via specific RNA-RNA interaction between U1 snRNA and EIciRNAs.

So, @stcordova, just how many introns end up in circular RNAs? What percent of all introns is this?