Mice that are homozygous for the mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Screening of third generation mice (G3) on standard chow identified a 11 week old male (born 11/8/2004) with a heart rate of 805 bpm. Repeat testing one week later confirmed the phenotype (822 bpm). This mutant mouse strain may be useful in studies of tachycardia.
This phenotypic deviant was identified following multidose ethylnitrosourea (ENU) treatments to induce mutations in male founder C57BL/6J mice (Stock No. 000664), in complex heart, lung, blood, and sleep disorders at the Mouse Heart, Lung, Blood, and Sleep Disorders (HLBS) Center at The Jackson Laboratory.