Fig. 7. Schematic diagrams of ITS regions from M. vaginatus and M. steenstrupii showing configurations and relative sizes of intergenic spacer regions (ISRs). The tRNA^Ile gene is shown in dark shading, with the tRNA^Ala gene shown in lighter shading. Fragments of the tRNA^Ile gene are present in some ribosomal operons of M. vaginatus, and are considerably shorter than the full gene.