The 3' C/D domain (U4-8) was also cloned previously by Darzacq and called U91. Both the doublet (U12-22/U4-8) and singlet (U4-8) forms of this snRNA have been purified from HeLa cells.
A portion of the 3' C/D domain (U4-8), previously identified by Darzacq as U91, has also been cloned. Both the paired (U12-22/U4-8) and solitary (U4-8) forms of this small nuclear RNA have been isolated from HeLa cells.