Skip to main content
. Author manuscript; available in PMC: 2014 Jan 1.
Published in final edited form as: Dev Biol. 2012 Oct 23;373(1):149–162. doi: 10.1016/j.ydbio.2012.10.017

Figure 1. Expression pattern of Hcn4 mRNA by whole-mount in-situ hybridization.

Figure 1

(A) At E8.5, Hcn4 was expressed throughout the heart tube in a caudal-to-cranial gradient. By E9.5 (B,C), expression was less in the atrial chamber, right ventricle (rv), and outflow tract (oft) than in other areas. At E10.5 and E11.5 (D–H), Hcn4 was strongly expressed in the sinus horns (sh) 27 and their interface with the atria, and at lower levels in the atria and ventricles. At E12.5 (I), Hcn4 was expressed highly in the sinoatrial node, the sinus venosus contribution to the atria including the coronary sinus (cs), and at lower levels in the ventricles and right atrium. In the neonatal heart (J,K), Hcn4 was expressed in the SA node, the sinus venosus derivatives, and the AV ring tissue. In (L) the ventricles are shown after clearing. A low-intensity meshwork of staining is visible, consistent with the His-Purkinje system (arrowheads delineate an example of a Purkinje fiber strand in the left ventricle). Abbreviations: ra, right atrium; la, left atrium; v, ventricle; rv, right ventricle; lv, left ventricle; sh, sinus horns; sv, sinus venosus oft, outflow tract; cs, coronary sinus.