Fig. 3.

Thin section electron micrograph of an intercalated disc in a cardiac-specific CKO mouse (from Gutstein et al., 2003). Intact adherens junctions (white arrowheads) and desmosomes (black arrowheads) are observed. While there are no gap junctions (and thus no perinexii) between ventricular myocytes in the CKO mutant mouse, intercalated disk regions of extremely close contact between cells are still observed (inset). Asterisks indicate a number of locations with membrane-membrane contacts of <30 nm, i.e., below the “Mori limit.” Bar = 140 nm.