Evolution of the MIR Elements Located in Coding Regions of Human Genome

Abstract

Mammalian interspersed repeats (MIRs) are classical tRNA-like SINEs of 260 bp in length, whose sequences are substantially diverged. The evolution of mammalian MIRs is now considered as a part of a common evolution of a CORE-SINE repeat family bearing a generic CORE-SINE that has been spread by borrowing reverse transcriptase from different LINE families by addition of the 3’ end containing the binding site for this enzyme [2]. The age of MIRs has been suggested of about 550 million years [2, 5]. In addition to the origination and spreading of MIRs, there is another aspect of the repeat evolution, their influence on a host genome. Unlike the Alu elements, whose role in a genome has been well studied, very little is known about the consequences of the MIR insertion. Here we have tried to focus on the MIRs evolution in the translated regions of human genes, using our own high powerful program for a search MIRs in the GenBank.