Psen1^tm2.1Shn

A single loxP site was inserted into intron 1 and a loxP-flanked hygromycin and thymidine kinase selection cassette was inserted into intron 3. Exons 2 and 3 and the drug selection cassette were removed in ES cells by transient Cre expression in ES cells prior to the production of mice. The final allele has a single loxP site in place of exons 2 and 3. (J:71606)