Multiple sequence alignment of three canonical reference sequences (Alu Jo, Alu Sc, and Alu Sp) with the new consensus sequences described in this work. Identical sequence residues are indicated by ".". Indels events are indicated by "-". Diagnostic mutations characteristic of Alu Sc and Alu Sp that are shared by the new consensus sequences are shaded. Substitutions distinguishing all Alu T subfamily members from Alu Sc are boxed.