Congenic mice confirm the presence of linked loci on chromosome 3 and 5 that influence stem cell number.

Relative numbers of eHPCs and HSCs per femur of the congenic animals B6.DBA chr.3 [14-33 cM]/chr.5 [8-29 cM/B6] and DBA.B6 chr.3 (19-60 cM)/chr.5 (5-38 cM) compared with their background strain (either B6 or DBA) are shown. The inbreeding coefficient for the line B6.DBA is 0.98; the remaining 2% donor genomic background was different in each animal and did not include any other mapped linked loci. The homozygous line DBA.B6 shows an inbreeding coefficient of more than 99%.P < .05 for B6.DBA versus DBA.B6; n = 3 (BM pooled from 6 animals) for DBA.B6 and n = 6 for B6.DBA. Mean values ± 1 SEM are shown.