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 calcium chloride intake (LOD=3.8) and preference (LOD=4.3) mapped to 90 Mb on mouse Chromosome 11 near D11Mit285. This locus is named Drinkcacl25 (drink calcium chloride 2 5). C57BL/6J-derived alleles at Drinkcacl25 confer increased calcium chloride intake and preference. Drinkcacl25 explains 3.8% of the calcium chloride intake variance and 4.1% of the calcium chloride preference variance.
Analysis Tools