These mice possess loxP sites on either side of exon 2 of the Dchs1 gene. The flanked region involves the first six cadherin domains as well as the initiator methionine and signal peptide.When these mice are bred to mice that express Cre recombinase, the resulting offspring will have the flanked sequence deleted in cre-expressing tissues.
Widespread knockout of Dchs1 (e.g. through crosses with the Tg(Sox2-cre)1Amc strain (Stock No. 004783)) causes defects in multiple internal organs, including kidney, heart, lung and skeleton. Cochleas of homozygous knockouts are shorter than those of wildtype mice. The kidneys are small and cystic. At birth, the lungs are smaller and the intestinal length is reduced. The skeleton exhibits abnormal ossification patterns in the sternum. Although born at predicted Mendelian ratios, homozygous mutants exhibit a variable neonatal lethality, sometimes surviving for two weeks. Homozygous knockout pups are similar in size to their wildtype siblings, but they often have a bent spine and curly tails. They show some signs of postnatal development, such as hair formation, but fail to grow.
