Microsatellite mapping of 9p LOH in JAK2V617F-homozygous colonies. (A) Microsatellite mapping of 68 JAK2V617F-homozygous colonies from patient PV26 (patient codes are the same as in Figure 1). The panel of microsatellite markers on chromosome 9 is shown on the left (distances are to scale between the telomere and D9S2148), from which informative markers were selected for each patient. Three patterns of microsatellite markers were observed in colonies from this patient, indicating 3 distinct LOH breakpoints. Each subclone is represented by a vertical line denoted A (60 colonies), B (4 colonies), or C (4 colonies), with markers showing heterozygosity in green and those showing LOH in red. Example traces from fluorescence microsatellite PCR are shown for 2 markers (D9S925 and D9S1817) for the 3 subclones (right), with the position of alleles shown by arrowheads. (B) Microsatellite mapping of 5 JAK2V617F-homozygous colonies from patient ET29. Two patterns of microsatellite markers were observed; example traces are shown for 2 markers (D9S43 and D9S1817) on the right. (C) Microsatellite mapping of JAK2V617F-homozygous colonies in 8 other patients. The panel of markers is the same as in panel A. Numbers of colonies corresponding to each pattern are shown above.