Tos17 insertions and expression of genes near the Pish locus. (A) Tos17 insertion sites in the 55-kb genomic region containing the Pish locus are indicated by arrows. Downward arrows indicate insertions with Tos17 oriented in the same direction as Pish and the Npi37-1 to Npi37-3 genes. Upward arrows indicate insertions in the opposite orientation. The black boxes indicate genes. (B) RT-PCR analysis of the four NLR genes. One microgram of total RNA isolated from NB callus was used. A series of 26, 30, and 32 cycles of amplification was used for the PCR. The experiment was repeated three times, and typical results are shown. Genomic DNA isolated from NB callus was used as a control for PCR efficiency by each primer pair.