Recently, a new genetic process termed RNA editing has been identified showing insertions and deletions of nucleotides in particular RNA molecules. On the other hand, there are a few non-random statistical properties in genes: in particular, the periodicity modulo 3 (P3) associated with an open reading frame, the periodicity modulo 2 (P2) associated with alternating purine/pyrimidine stretches, the YRY(N)6YRY preferential occurrence (R = purine = adenine or guanine, Y = pyrimidine = cytosine or thymine, N = R or Y) representing a "code" of the DNA helix pitch, etc. The problem investigated here is whether a process of the type RNA editing can lead to the non-random statistical properties commonly observed in genes. This paper will show in particular that:u-The process of insertions and deletions of mononucleotides in the initial sequence [YRY(N)3]* [series of YRY(N)3] can lead to the periodicity modulo 2 (P2).-The process of insertions and deletions of trinucleotides in the initial sequence [YRY(N)6]* [series of YRY(N)6] can lead to the periodicity modulo 3 (P3) and the YRY(N)6 YRY preferential occurrence.-Furthermore, these two processes lead to a strong correlation with the reality, namely the mononucleotide insertion/deletion process, with the 5' eukaryotic regions and the trinucleotide insertion/deletion process, with the eukaryotic protein coding genes. © 1992 Academic Press Limited All rights reserved.
