Uridine Deletion/Insertion RNA Editing

Cryptogene	A gene whose transcript is edited.
Guide RNA	(aka gRNA) A short 3'-uridylated RNA that can form a perfect duplex (except for the oligo[u] tail) with a stretch of mature edited mRNA. G-U base pairing is allowed.
Anchor Duplex	The RNA duplex formed by hybridization of the 5' end of the gRNA and the mRNA sequence just downstream of the first editing site in an editing block.
Pre-Edited	A pre-edited region or sequence will be edited in the mature mRNA.
Unedited	An unedited region or sequence will never be edited in the mature mRNA.
Editing Block	Edited mRNA sequence mediated by a single gRNA.
Editing Domain	Edited mRNA sequence mediated by two or more overlapping gRNAs.
Pan-Edited Gene	Extensively edited.
3' oligo[U] Tail	The string of non-encoded U's at the 3' end of the gRNA
gRNA-mRNA	A gRNA-mRNA chimera consists of a gRNA 5' end covalently bound to an mRNA 3' end, oft at an editing site.

Model for U-Insertion RNA Editing

The gRNA's A's and U's guide addition of U's to the mRNA.

Hybrid	Hybridization of gRNA to mRNA just downstream of ES1. Perhaps mediated by an RNA chaperone.
Cut	Endonuclease cuts mRNA at mismatch.
U Insertion	3' TUTase (terminal uridyl transferase) adds U's to 3' end of 5' mRNA fragment.
RNA Ligase	RNA ligase ligates the cut mRNA fragments back together.

Model for U-Deletion RNA Editing

If the mRNA's U's are not base-paired in the gRNA, they are removed.

Hybrid	Hybridization of gRNA to mRNA just downstream of ES1. Perhaps mediated by an RNA chaperone.
Cut	Endonuclease cuts mRNA at mismatch.
U Deletion	3'-5' exonuclease removes bulged (unpaired) U's from mRNA.
Ligation	RNA ligase ligates the cut mRNA fragments back together.