RMCE of TardbpGt(D045A10)Wrst inserted the human cDNA encoding the amino acid substitution of threonine for alanine at position 315 (A315T). This mutation is found in patients with amyotrophic lateral sclerosis (ALS). Cre-mediated recombination removed the hygromycin resistance cassette. Western blot analysis confirmed increased expression of the modified allele. (J:214706)