ANTISENSE OVERLAPPING OPEN READING FRAMES IN GENES FROM BACTERIA TO HUMANS

Long Open Reading Frames (ORFs) in antisense DNA strands have been rep orted in the literature as being rare events. However, an extensive an alysis of the GenBank database revealed that a substantial number of g enes from several species contain an in-phase ORF in the antisense str and, that overlaps entirely the coding sequence of the sense strand, o r even extends beyond. The findings described in this paper show that this is a frequent, non-random phenomenon, which is primarily dependen t on codon usage, and to a lesser extent on gene size and GC content. Examination of the sequence database for several prokaryotic and eukar yotic organisms, demonstrates that coding sequences with in-phase, 100 % overlapping antisense ORFs are present in every genome studied so fa r.