Abstract
The statistical analysis of 5′ flanking regions of eukaryotic tRNA genes was done. The analysis of nucleotides in the sequence of fungi and invertebrates showed a high content of A and T in the flanking regions versus coding regions where C and C dominate. In contrast to these results in vertebrates sequences the preferences of any nucleotide in flanking regions was not observed. The analysis of tetrads showed five conserved signals: TTCT, (T/A)(T/A)ATA, A(C/T)(C/A)A in the tRNA genes of fungi, (A/T)TCA of invertebrates and (A/T)CAC of vertebrates. The analysis of 3′ flanking regions did not show any conserved signals except well known poly-T tracks.