Homozygotes: A targeting vector was designed to insert a neomycin resistance (neo) cassette into exon 6 of the solute carrier family 12, member 2 (Slc12a2 or Nkcc1) gene, abolishing gene function. Homozygous mice are viable, fertile, and exhibit growth retardation with a 30% incidence of death by the time of weaning. Nkcc1 regulates cell volume and is expressed in vascular endothelial cells where it is required for controlling cytosolic concentrations of Cl- and K+, and in the basolateral membranes of epithelial cells where it provides an entry pathway for ions that are secreted across the apical membrane. These Nkcc1-/- mice are significantly smaller than their wildtype littermates by 1 week of age, and remain 80% smaller as adults. They are deaf, have less body fat, reduced mean arterial blood pressure, and exhibit reduced cAMP-induced short circuit currents in jejunum, cecum, and trachea. These mutant mice also demonstrate unusual head postures, and engage in circling behaviors and rapid spinning, but have difficulty maintaining their balance. The lumen of the cochlear duct of these mice is collapsed, and Reissner's membrane lies against the interdental cells of the spiral limbus, the tectorial membrane, and the stria vascularis. These mice may be useful for studying the regulation of cell volume, and the control of Cl- and K+ secretion in the maintainance of hearing and blood pressure.

Heterozygote: Heterozygous mice are viable, fertile, and normal in size. They exhibit normal growth, and are phenotypically similar to wildtype mice with the exception of slightly reduced blood pressure.

These Slc12a2 (or Nkcc1) knockout mice exhibit growth retardation with a 30% incidence of death by the time of weaning. They are deaf, have less body fat, reduced mean arterial blood pressure, exhibit reduced cAMP-induced short circuit currents in jejunum, cecum, and trachea, unusual head postures, and engage in circling behaviors and rapid spinning, but have difficulty maintaining their balance. These mice may be useful for studying the regulation of cell volume, and the control of Cl- and K+ secretion in the maintenance of hearing and blood pressure.

This strain is hosted by NIH's MMRRC, which partners with JAX for the distribution of this and other strains. For additional information and to purchase, please visit the MMRRC site.