PCR Typing of Alu Elements — Molecular Genetics and Forensic Application

Abstract

Alu repeats belong to the family of short interspersed elements (SINEs) and are among the most abundant repetitive DNA sequences in the mammalian genome. They represent mobile genetic elements ancestrally derived from the 7SL RNA gene and have presumably spread within the genome by retroposition (reviewed in [1]). A particular group of Alu repeats appears to be human-specific (HS subfamily) and has expanded only recently within the human genome as indicated by distinct dimorphisms at various loci due to the presence or absence of an Alu repeat. In recent extensive studies, the frequency distributions of Alu insertions at selected loci in various human racial groups and populations were determined. Significant differences in frequency distribution between these populations were observed which could be used to determine the evolutionary origin as well as the phylogenetic relationship between racial groups [2,3]. These genetic markers should therefore be useful to obtain clues on the race of an unknown stain donor in forensic casework. In the present study, we have determined the frequency and segregation behaviour of Alu insertions at six loci in the German population.