Rb1^tm1Jyjw

Aspartic acid to alanine (D879A) and glycine to glutamic acid (G880E) mutations were introduced into the caspase cleavage site of exon 25 and a diagnostic EcoRI site was introduced into intron 24 via homologous recombination. A floxed neo cassette was also inserted into intron 25. Correctly targeted ES cells subjected to caspase activation did not show diminishment of Rb protein, thus confirming the mutation to the caspase cleavage site. (J:80087)