Tsc1^tm1.1Djk

A floxed neo-TK cassette was inserted into the intron preceding exon 17 and a third loxP site was introduced downstream of exon 18 by homologous recombination. Transient expression of cre recombinase in correctly targeted ES cells excised the entire region contained within the 3 loxP sites resulting in a frame shift and premature translation termination. Deletion of exons 17 and 18 in ES cells was confirmed by PCR analysis. Homozygous mutant embryos were identified by PCR genotyping but could not be observed past E13.5. Western blot analysis demonstrated the absence of protein expression in mouse embryonic fibrobasts (MEFs) derived from E10-E10.5 homozygous mutants embryos. (J:75243)