(a) Representative Flt3-ITD PCR analysis of a panel of murine rAMLs run on a 2% agarose gel. The normal amplicon size is 333 bp. Presence of Flt3-ITD is indicated by an additional larger band on the gel. The gel is loaded as indicated above the image. ‘CBA' and ‘C57' refer to normal spleen DNA from CBA/H and C57BL/Lia, respectively; ‘Brain' refers to brain tissue from the animal in which AML A developed and represents a normal tissue control; and AMLs A–F refer to independent AML samples. The genetic alterations identified in the AMLs are summarised below each sample (Flt3-ITD: +, presence and −, absence; del2: +, presence and −, absence; nucleotide 703 base at nucleotide 703 of Sfpi1/PU.1. C is wild type and T is mutant (the T allele leading to arginine 235 being converted to cysteine in Sfpi1/PU.1 protein). (b) CBA Flt3 Exon 14 and 15 sequence illustrating the three insertion sites and sequence of Flt3 ITD in AMLs A–C. ITD lengths for each are 18, 27 and 36 bp, respectively. (c) Predicted Flt3 protein sequence of AMLs A–C showing inserted amino acids.