A) End point PCR is performed with primers targeting the 5’ and 3’ never edited regions present at the ends of all pan-edited RNAs to amplify all versions of a given RNA (pre-edited, partially edited, fully edited). Green, never edited; pink, fully edited; yellow, junction region; blue, pre-edited. B) Agarose gel analysis of full gene PCR amplicons of ATPase 6 RNA in cells either expressing (+) or depleted of (-) MRB3010 or TbRGG2. Red dots indicate products that accumulate in the absence of each protein. Note that pre-edited RNA accumulates upon MRB3010 depletion but not upon TbRGG2 depletion, signifying a role in editing initiation for the former, but not the latter.