FIG. 1.

Map of the prokaryotic ribosomal operon and positions of primer pairs RTS1-RTS2 and RTS1-RTS4 for amplification by PCR of the P. salmonis ITS. The map is drawn to scale for the ITS section based on the P. salmonis LF-89 ITS sequence (the first 18 nucleotides at the 5′ end of primer RTS4 are located at the beginning of the 23S rRNA gene). The rRNA genes are drawn to a different scale, and the lengths are based on the lengths of these genes in the E. coli rRNA operon.