Signal sequences in intron equivalents

The 5' and 3' ends of each intron are marked with GU and AG dinucleotide sequences; a short tract of poly-pyrimidines (C or T) also occurs near the 3' end ahead of the AG singal.

[Note: exons and introns occur in the DNA sequence as expressed and intervening sequences: hnRNA products transcribed off the DNA template strand include exon and intron equivlaents. ]

Figure © 2012 TA Brown, Introduction to Genetics (1st ed.); additional text © 2014 by Steven M. Carr