Pdlim7 is dynamically expressed in actin-rich structures throughout murine development.

<p>β-galactosidase staining of whole mount embryos identifies <i>Pdlim7</i> early in the developing heart, forelimbs, hindlimbs, and somites (A-C). In E11.5 and E13.5 heart sections, β-galactosidase staining is localized to the trabeculated regions of the ventricles, atrial walls, and interventricular and atrial septa (D-E); of note: the β-galactosidase reaction time chosen does not reveal the lower levels of Pdlim7 expression in the cardiac cushion or valve cells. Sagittal sections of E18.5 embryos show Pdlim7 expression throughout the smooth muscle, including the lung alveoli, stomach, aorta, and bladder (F). Immunostaining of E11.5 hearts demonstrates Pdlim7 (green) localization to the outflow tract and atrioventricular cushions with MF20 positive myocardial cells (red) (G). Pdlim7 (green) proteins are also detected in the epicardium of E13.5 embryos (arrows, H-I) with MF20 positive myocardial cells (red) and DAPI nuclei (blue). In the aorta, Pdlim7 proteins (green) localize to filamentous actin (red) of smooth muscle, but not PECAM-positive endothelium (white) (arrows, J-L), control DAPI nuclei (blue). Scale bar = 200μm (D-E) and 50 μm (F, I, L). Ao = Aorta; AVC = atrioventricular cushion; Blad = bladder; LA = left atrium; LV = left ventricle; OFT = outflow tract; RA = right atrium; RV = right ventricle.