Experiment
Genetic loci associated with body composition were mapped using 369 animals from a (C57BL/6J x CASA/Rk)F2 intercross. A panel of 255 polymorphic markers at an average spacing of 5.9 cM was used for genome scan. Parental strain C57BL/6J displays decreasedactivity and increased weight, lean tissue mass, abdominal fat mass, body length, bone mineral density (BMD), bone area, and bone mineral content (BMC) compared to parental strain CASA/Rk. Males from C57BL/6J display increased body mass index (BMI) and total body fat tissue mass (FTM) compared to males from CASA/Rk.
Linkage to bone area mapped to 53 cM on mouse Chromosome 7 and is named Ba1 (LOD=4.71). Linkage to bone area in males is named Ba4 and also mapped to 53 cM with LOD=4.12. Linkage to bone mineral content to 15 cM (Bmc3, LOD=4.42), and mapped to 53 cM (Bmc8, LOD=3.45) in males.