Figure 1.
Loss of CaSR mRNA and protein during lactation in CaSR-cKO mice. A, Quantitative PCR for CaSR mRNA expression in control (CaSRlox/lox) and CaSR-cKO (BLG-Cre;CaSRlox/lox) mammary glands. Note the almost complete loss of CaSR expression in lactating mammary glands in the cKO mice. Bars represent the mean and SEM of 7 mice for each genotype. B, Western blots for CaSR expression in membrane extracts from kidneys and CaSR-cKO and control mammary glands run under nonreducing conditions. The predominant forms of the CaSR in mammary gland membranes appear to be multimers with molecular masses of approximately 160 and 250 kDa. There was no immunoreactive CaSR protein detected in membranes from cKO mammary glands. Kidney expressed CaSR isoforms predominantly of approximately 65 and of 140 kDa.