Ctsl^tm1.1Thre

Exon 2 was replaced with a modified exon 2 in which the conventional start codon M1 ATG was substituted by TTC. A floxed polyadenylation (STOP) sequence was inserted downstream of the modified exon 2. Flp-mediated recombination removed the FRT-flanked puromycin resistance cassette inserted into intron 2. This approach generates a constitutive null allele with the potential to express an M1-mutated cathepsin L mRNA from the endogenous gene locus. (J:216506)