EDITING OF RPS3 RPL16 TRANSCRIPTS CREATES A PREMATURE TRUNCATION OF THE RPL16 OPEN READING FRAME

Overlapping open reading frames corresponding to maize mitochondrial g enes rps3 and rpl16 have been found in Petunia mitochondrial DNA. The DNA region associated with these two genes is part of the Petunia mito chondrial recombination repeat and is iterated three times. Analysis o f transcripts from these genes shows that there is RNA editing of the coding regions and that one of the editing sites detected in the open reading frame overlap creates a premature stop codon in the rpl16 sequ ence. No transcripts were detected that were unedited at this site. Th us, in Petunia editing of rpl16 appears to render this gene nonfunctio nal.