QTLs for the B220%, CD4%, and CD8% phenotypes in BXD RI mice.

Peripheral blood B220%, CD4%, and CD8% were measured in 35 BXD RI strains for QTL mapping by using predetermined genotype data and the Map Manager QTXb11 software, both available from The Jackson Laboratory (http://www.bioinformatics.jax.org) Web site.56Two QTLs were defined for the B220% phenotype (A), designated peripheral blood B cell percentage 1 (Pbbcp1, LOD 4.1,P < .00001) and Pbbcp2 (LOD 3.7,P < .00004), on chromosome 1 (Chr 1) at 63.1 cM and 48.4 cM, respectively. A suggestive locus was found for the CD4% phenotype (LOD 2.6, P < .000 57) at 73 cM on Chr 8 (B). A QTL for the CD8% phenotype, peripheral blood cytotoxic T lymphocyte percentage 1 (Pbctlp1, LOD 3.8, P < .000 02), was mapped to the 9- to 24-cM region of Chr 19 (C).