[Evolution of Alu repeats: dynamics of distribution in genome].

A mathematical model of evolutionary dynamics of Alu repeats' number in the human genome has been worked out. The model permitted us to observe the dynamics of propagation of Alu repeats within the genome and to evaluate such important parameters of the process mentioned as the rates of transposition (insertion of new copies into the genome) and excision of repeats. The peculiarities of the control of Alu repeats' number in the genome have been discussed, based on the data obtained.

[tRNA as a possible primer for the initiation of reverse transcription of dispersed repeats Alu, B1, B2 and L1].

The contextual analysis of the primary structures of 28 various dispersed repeats Alu, B1, B2 and L1 (Kpn1) of primates and rodent genomes has been carried out to search for the regions complementary to the 3'-ends of the known at present tRNA of these organisms. It has been shown that the abundance of the investigated repeats contain the regions revealing marked and statistically non-random complementarity to the 3'-end of at least one of the tRNA considered. Taking into account the retroviruses replication model known from literature these revealed regions are considered as potential primer-binding sites for the initiation of reverse transcription of the mentioned repeats or more long DNA fragments containing them.

[Evolution of Alu repeats. Imitation model].

At present, nucleotide sequences of 100 different Alu repeats are known, i.e. 0.

[Distribution of Alu repeats along the human genome: formation of clusters and features of insertion regions].

The contextual analysis of nucleotide sequences of 22 Alu repeats arrangement regions in the human genome has been carried out and some of their peculiarities have been revealed. In particular, the occurrence of marked and statistical non-random homology between the repeats and the regions of their integration has been shown. A mechanism of choosing the Alu repeats insertion regions in the genome has been suggested taking into account these peculiarities.

[Various aspects of evolution of Alu repeats in mammals].

A complex study on various evolutionary peculiarities of the mammalia dispersed Alu repeats (Alu repeats of primates and B1 of rodents) has been carried out by phylogenetic analysis. A phylogenetic tree, containing the 7SL RNA genes and the Alu repeats of primates and rodents has been constructed. It has been shown that the branch of the phyletic line leading to the Alu repeats of primates and B1 of rodents from the 7SL RNA genes occurred after the divergence of the 7SL RNA genes of amphibia and mammalia, but before the divergence of the 7SL RNA genes of primates and rodents (250.