ALU SEQUENCES

Alu sequences are frequently encountered during study of human genomic nucleic acid and form a major component of repetitive DNA. This revie w describes the origin of Alu sequences and their subsequent amplifica tion and evolution into distinct subfamilies, In recent years a number of different functional roles for Alu sequences have been described, The multiple influences of Alu sequences on RNA polymerase II-mediated gene expression and the presence of Alu sequences in RNA polymerase I II-generated transcripts are discussed. (C) 1997 Federation of Europea n Biochemical Societies.