Pathogenesis of cardiomyopathy

Disclosed is a mouse, cells derived therefrom, and methods for using the mouse, the mouse being homozygous for a disrupted δ-sarcoglycan gene, the disruption in the gene having been introduced into the mouse or an ancestor of the mouse at an embryonic stage. The disruption prevents the synthesis of functional δ-sarcoglycan in cells of the mouse and results in the mouse having a reduced amount of β- and ε-sarcoglycan and sarcospan, and a disruption of the sarcoglycan-sarcospan complex in smooth muscle of the mouse. Also disclosed is a mouse, cells derived therefrom, and methods for using the mouse, the mouse being homozygous for a disrupted β-sarcoglycan gene, the disruption in the gene having been introduced into the mouse or an ancestor of the mouse at an embryonic stage. The disruption prevents the synthesis of functional β-sarcoglycan in cells of the mouse and results in the mouse having a reduced amount of δ-and ε-sarcoglycan and sarcospan and α-dystroglycan in smooth muscle of the mouse.