[Evolution of Alu repeats. Imitation model]

Abstract

At present, nucleotide sequences of 100 different Alu repeats are known, i.e. 0.01% of the total number of Alu repeats in the genome. It is clear that one can not refer the evolutionary characteristics of Alu repeats obtained from the analysis of the available limited sample to all Alu repeats comprised in the genome, without additional statistical estimations. For supplementary investigation of such average evolutionary characteristics as the extent of intraspecific divergence, the rate of Alu repeats transposition (insertion, excision), we used the method of imitation simulation of the process of Alu repeats transposition in the genome. As a result of simulation, phylogenetic relations were obtained among all Alu repeats. It was shown that the evolutionary characteristics evaluated for different samples of repeats were similar. It was proved that the extent of divergence of Alu repeats in the model is twice as small as that evaluated, according to the real data (0.15, instead of 0.3). Possible reasons for such discrepancy have been discussed.