Abstract: Disclosed within is a mouse, and cells derived therefrom, which are homozygous for a disrupted &dgr;-sarcoglycan gene, the disruption in said gene having been introduced into the mouse or an ancestor of the mouse at an embryonic stage. Said disruption prevents the synthesis of functional &dgr;-sarcoglycan in cells of the mouse and results in the mouse having a reduced amount of &bgr;- and &egr;-sarcoglycan and sarcospan, and a disruption of the sarcoglycan-sarcospan complex in smooth muscle of the mouse. Said disruption also results in a reduced amount of sarcospan, &agr;-, &bgr;-, &ggr;-, and &egr;-sarcoglycan in the sarcolemma of skeletal and cardiac muscles of the mouse, compared to the amounts of said components in a mouse lacking disrupted &dgr;-sarcoglycan genes. Preferred specific disruptions of the &dgr;-sarcoglycan gene are listed.

Abstract: Disclosed is a mouse, cells derived therefrom, and methods for using the mouse, the mouse being homozygous for a disrupted &dgr;-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 &dgr;-sarcoglycan in cells of the mouse and results in the mouse having a reduced amount of &bgr;- and &egr;-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 &bgr;-sarcoglycan gene, the disruption in the gene having been introduced into the mouse or an ancestor of the mouse at an embryonic stage.