Mouse Genome Informatics
involves: 129S1/Sv * 129X1/SvJ * C57BL/6
phenotype observed in females
phenotype observed in males
N normal phenotype

Junctional sarcoplasmic reticulum lacks its visible content, and overall sarcoplasmic reticulum volume is increased in ventricular myocytes of Casq2tm1Klmn/Casq2tm1Klmn mice

cardiovascular system
• approximately 10% increase in heart to body weight ratio
• modest but statistically significant increase in ventricular wall thickness
• display a significantly slower heart rate but normal cardiac contractility, normal left-ventricular cavity size, and unchanged ECG parameters
• homozygous mice were viable and fertile
• exposure to catecholamine in homozygous mice myocytes caused polymorphic nonsustained ventricular tachycardia, a phenocopy of the human arrhythmias
• exhibited striking increases in sarcoplasmic reticulum volume and surface area
• exposure to catecholamines caused increased diastolic sarcoplasmic reticulum Ca2+ leak