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.
On mouse Chromosome 7, significant linkage to potassium chloride intake mapped to 144 Mb near D7Mit223 (LOD=6.5). This locus explains 6% of the phenotypic variance and is named Drinkkcl2 (drink potassium chloride 2). C57BL/6J-derived alleles at Drinkkcl2 confer increased potassium chloride intake.