Formation of the Lariat Structure during removal of intron equivalents

The donor site is joined covalently to the branch site, the covalent structure is clipped out at the acceptor site, and the 3' and 5' ends of the adjacent exons are joined. The RNA 'lariat' structure is subsequently degraded

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