Atxn7^tm1Hzo

The polyglutamine tract in exon 3 was expanded to 266 CAG repeats via homologous recombination. A single loxP site remained downstream of exon 4. While levels of mutant and wild-type transcript were similar in heterozygous mutant mice, immunostaining of brain tissue indicated increased levels mutant protein. The number of CAG repeats did not decrease by more than 10 (30 nt) in the two lines initially studied. Naturallly occurring contracted mutations of the 266Q tract have been observed, resulting in 230 and 100 CAG repeats. (J:82072, J:179021)