FTP, name these regions of DNA that are transcribed but do not appear in the mRNA product, unlike exons.
The most extensive set of them has been located in the ovalbumin gene of chickens. This followed their discovery in 1977 by Sharp and Roberts, who won a Nobel for their work.  That discovery occurred in the beta-globin gene in mice, where the largest of them was found to be 550 nucleotides long.  Those molecules that contain them are called ribozymes, referring to how they are removed via self-excision.  FTP, name these regions of DNA that are transcribed but do not appear in the mRNA product, unlike exons.
The most extensive set of them has been located in the ovalbumin gene of chickens.
introns