Dolph Houben

125 Transplant chimerism in bone VCA 6 Cross-section of allotransplant Genomic DNA recovered from pulverized cross-sections was also studied. SRY gene copy numbers were similarly expressed as a ratio to the housekeeping gene. Ten of 11 DNA samples obtained from a cross-section of the allotransplant expressed SRY. The mean relative SRY gene copy number was 1.97x10 -7 (SD 2.91x10 -7 ) in group 1, 2.32x10 -6 (SD 2.99x10 -6 ) in group 2, and 1.0x10 -2 (SD 1.0x10 -2 ) in male controls. Group one had a significantly lower SRY copy number than male controls (Fig. 6). Group 2 copy numbers did not reach a similar significance when compared with either male control bone or Group 1 data (Fig. 6). Calculation of the percentage of SRY present in the allotransplant compared to male control samples, showed no significant difference in the presence of the SRY gene between the two groups, although the patent AV bundle group had a lower mean percentage (mean 1.7 x10 -3, SD: 2.5x10 -3 ) compared to the ligated group (mean:1.7x10 -2 , SD: 2.4x10 -2 ). The lower proportion of SRY found in allotransplant cross-sections reflects a smaller percentage of male cells in the representative section of the allotransplant and thus the extent of repopulation (Fig. 7). Figure 6: q-PCR analyses of gDNA extracted from pulverized transverse bone sections. SRY was detected in both groups. Group 1 had a significantly lower copy number (p=0.04) compared to male control samples. Mean relative copy number SRY in the AV+ group:1.97x10 -7 (SD 2.91x10 -7 ), AV- group: 2.32x10 -6 (SD 2.99x10 -6 ), Male control: 1.0x10 -2 (SD 1.0x10 -2 ), H2O control samples were not detected.