Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  4
• Reference
  J:75340 Clise-Dwyer K, et al., Genetic studies of B-lymphocyte deficiency and mastocytosis in strain A/WySnJ mice. Immunogenetics. 2001 Dec;53(9):729-35
• ID
  MGI:2385444

Genes

Gene	Assay Type
Bcmd2	visible phenotype
D4Mit204
D4Mit190

Notes

• Experiment
  A second locus affecting B-lymphocyte deficiency and mastocytosis, Bcmd2, was mapped to an interval on mouse Chromosome 4 between D4Mit204 and D4Mit190 using an (A/WySnJ x CAST/Ei)F2 cross and controlling for Bcmd1 on chromosome 15. Parental strain A/WySnJ exhbits defective B-cell and mast cell homeostasis whereas parental strain CAST/Ei does not. Bcmd2 reached an LRS significance level of >10.4 between D4Mit204 and D4Mit190. Bcmd2 is a minor modifying locus controlling approximately 15% of the phenotypic difference. The Bcmd1 locus was fine-mapped to a 1.8 cM interval between D15Mit259 and D15Mit118 using extreme progeny from the (A/WySnJ x CAST/Ei)F2 cross and 630 animals from an (A/WySnJ x CAST/Ei)F1 x A/WySnJ backcross. A potential candidate gene for Bcmd1 is Blk. Bcmd1 and Bcmd2 were further verified in congenic strains created by introgressing either the Bcmd1 or Bcmd2 locus from CAST/Ei donor DNA onto the genetic background of A/WySnJ. Interestingly, the AW.CAST-Bcmd2^CAST/Ei congenic exhibits mastocytosis but not B-lymphocyte deficiency suggesting mastocytosis is controlled by a different gene or genes.