title: A quantitative-trait locus controlling peripheral B-cell deficiency maps to mouse Chromosome 15.
abstract: Peripheral B-lymphocyte homeostasis is determined through incompletely defined positive and negative regulatory processes. The A/WySnJ mouse, but not the related A/J strain, has disturbed homeostasis leading to peripheral B-lymphocyte deficiency. B lymphopoeisis is normal in A/WySnJ mice, but the B cells apoptose rapidly in the periphery. This B cell-intrinsic defect segregated as a single locus, Bcmd, in (A/WySnJxA/J)F2 mice. Here we mapped a quantitative-trait locus (QTL) that contributes to the A/WySnJ B-cell deficiency by examining the F2 progeny of a cross between strains A/WySnJ and CAST/Ei. In this cross, minimally 1.9 QTLs controlling peripheral B lymphocyte deficiency segregated. The (A/WySnJxCAST/Ei)F2 mice were phenotyped for splenic B-cell percentage and the DNA from progeny with extreme phenotypes was used to map the QTL by the simple-sequence length polymorphism method. A genome scan showed linkage between peripheral B-cell deficiency and Chromosome (Chr) 15 markers. When closely spaced Chr 15 markers were analyzed, the 99% confidence interval for the QTL map position extended along the entire chromosome length. The peak lod scores >17 occurred between 30 and 45 cM. We conclude that a significant QTL segregating in (A/WySnJxCAST/Ei)F2 mice resides in this middle region of Chr 15.
authors.affiliation: Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison, 53706, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Hoag
authors.forename: K
authors.initials: K
authors.lastname: Clise-Dwyer
authors.forename: Y H
authors.initials: YH
authors.lastname: Lim
authors.forename: F E
authors.initials: FE
authors.lastname: Nashold
authors.forename: J
authors.initials: J
authors.lastname: Gestwicki
authors.forename: M P
authors.initials: MP
authors.lastname: Cancro
authors.forename: C E
authors.initials: CE
authors.lastname: Hayes
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002452:Cell Count; D002874:Chromosome Mapping; D005260:Female; D008040:Genetic Linkage; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D019655:Quantitative Trait, Heritable; D051381:Rats