CNTRL-FGFR1 neoplasms are transplantable and originate from oligo- or monoclonal hematopoietic stem/progenitor cells. (A) Kaplan-Meier analysis of primary and secondary recipients shows no significant difference between the primary and secondary transplants. (B) Schematic representation showing the relative location of the PCR primers used to analyze the Tcrb locus (top). Gel electrophoresis of PCR products shows DJ arrangement of Tcrb in 2 representative, serially transplanted CNTRL-FGFR1 mice (bottom). DNA from BM displays 1 large band reflecting no rearrangement. DNA from normal Thy and lymph node (LN) shows several smaller bands resulting from rearrangements. DNA from Thy and LNs from 2 leukemic mice (#2, #5) shows oligo- or monoclonality. Specifically, DNA from 2 cell lines (CEP2A and CEP5A) shows only 1 predominant band (arrow), indicating that these lymphoma cells were monoclonal. (C) RT-PCR analysis shows the specific transcriptional levels of B-lineage genes in sorted myeloid cells (Gr1⁺Mac1⁺) or B cells (B220⁺CD19⁺) from normal (Nor) BALB/c mice as well as in sorted AML cells (Gr1⁺Mac1⁺ B220⁺) from 2 leukemic mice. The B-lymphoid cell line BBC2 is shown as a positive control. (D) Genomic PCR analysis of IgH rearrangement showing the germline configuration in DNA from the tail and polyclonal rearrangements in the B cells sorted from 3 normal BALB/c mouse splenocytes. The B220⁺Gr1⁺Mac1⁺ AML cells have the same pattern as normal Gr1⁺Mac1⁺ myeloid cells.