Experiment
Linkage analysis was performed on (C57BL/6J x PWK/PhJ)F2 animals to identify genetic loci associated with preference and intake of calcium and other salt compounds. Animals were subjected to a two-bottle choice test between water and one other solution (CaCl2, CaLa, MgCl2, KCl, NH4Cl, NaCl, citric acid, QHCl, or saccharin) for a period of 96 hours. PWK/PhJ is a high consumer of calcium chloride (CaCl2) and calcium lactate (CaLa) whereas C57BL/6J is a relatively low consumer. PWK/PhJ also consumes more MgCl2 compared to C57BL/6J. However, when consumption of KCl, NaCl and saccharin were analyzed, C57BL/6J animals consumed more of these solutions compared to PWK/PhJ animals. Linkage analysis was performed using 116 polymorphic markers at a resolution of 10cM - 30cM. Thirty QTLs reaching statistical significance were identified. Authors assigned separate QTL nomenclature for each of the salt compound QTL even if they mapped to the same linkage marker.
Significant linkage to potassium chloride preference mapped to 52 Mb on mouse Chromosome 15 near D15Mit143 (LOD=3.7). This locus is named Drinkkcl5 (drink potassium chloride 5). C57BL/6J-derived alleles confer increased preference for potassium chloride. Drinkkcl5 explains 3.6% of the phenotypic variance.