Identification and Simulation of New Non-random Statistical Properties Common to Different Populations of Eukaryotic Non-coding Genes

The autocorrelation function analysing the occurrence probability of the i -motif YRY(N)iYRY in genes allows the identification of mainly two periodicities modulo 2, 3 and the preferential occurrence of the motif YRY(N)6YRY (R = purine = adenine or guanine, Y = pyrimidine = cytosine or thymine, N = R or Y). These non-random genetic statistical properties can be simulated by an independent mixing of the three oligonucleotides YRYRYR, YRYYRY and YRY(N)6 (Arquès & Michel, 1990b). The problem investigated in this study is whether new properties can be identified in genes with other autocorrelation functions and also simulated with an oligonucleotide mixing model. o autocorrelation functions analysing the occurrence probability of the i-motifs RRR(N)iRRR and YYY (N)iYYY simultaneously identify three new non-random genetic statistical properties: a short linear decrease, local maxima for i ≡ 3[6] (i = 3, 9, etc) and a large exponential decrease. Furthermore, these properties are common to three different populations of eukaryotic non-coding genes: 5′ regions, introns and 3′ regions (see section 2). three non-random properties can also be simulated by an independent mixing of the four oligonucleotides R8, Y8, RRRYRYRRR, YYYRYRYYY and large alternating R/Y series. The short linear decrease is a result of R8 and Y8, the local maxima for i ≡ 3[6], of RRRYRYRRR and YYYRYRYYY , and the large exponential decrease, of large alternating R/Y series (section 3). ological meaning of these results and their relation to the previous oligonucleotide mixing model are presented in the Discussion.