Tor1aswap mutant mice possess loxP sites flanking exon 5 of the torsin family 1, member A (torsin A) Tor1a gene. They also contain a downstream mutant exon 5 with a ΔE knockin. Tor1a is an ATPases Associated with diverse Activities (AAA+) protein residing in the lumen of the ER/nuclear envelope (ER/NE) space. The in-frame ΔE deletion in TOR1A has been shown to cause the autosomal dominant disorder, DYT1 dystonia, which is characterized by abnormal, involuntary twisting movements and muscle contractions due to selective dysfunction of CNS motor circuits. Tor1aswap mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have wildtype exon 5 deleted, and will instead express the ΔE knockin in the cre-expressing tissues.
When mice are generated carrying one Tor1aswap allele, one Tor1aflox allele (from Stock No. 025832) and Cre from B6.Cg-Tg(Nes-cre)1Kln/J mice (from Stock No. 003771), they shoe reduced survival and surviving animals show decreased growth rate adn selective degeneration of CNS motor circuits. A similar phenotype is present in homozygous induced- ΔE KI mice with cre from Stock No. 003771. The increased dosage of torsin A in these animals suppresses the lack of function mediated growth deficiency but does not supress motor abnormalities.
