Introns are removed from eukaryotic RNA transcripts and exons are spliced together. This video shows the details of the process of removal of a typical nuclear intron, including the roles of the various SNRNPs. Includes the formation of the A, B, and C complexes, and the two transesterification reactions.
CC licensed images can be downloaded from my Flickr site in the "teaching" set. http://www.flickr.com/photos/agathman/