Figure 2

Modulation of cardiomyogenic potential of PE/ST explants by microRNA mimics administration Panels A–D. Representative image of chicken HH17 embryo before (panel A) and after (panel B) PE excision. Arrows demarcates the PE. Panel C illustrates PE culturing just right after dissection (panel C) and 24 h after culturing (panel D). Panel E represents an schematic overview of the experimental design. Panel F shows qPCR results of cardiomyogenic (Nkx2.5, Mef2c, Gata4, Mhy15, Tnnt2) markers expression after microRNA mimic administration in HH17 PE/ST explants. Observe that miR-23 and miR-27 over-expression leads to down-regulation of all cardiomyogenic markers, miR-100 does not modify most of them and miR-223, miR-195, miR-125 and miR-146 increased terminally differentiation markers such as cardiac troponin T (Tnnt2). Confocal image analyses of cTnI expression in controls (panels G-J), miR-27 (panels K-N) and miR-195 (panels O-R) treated HH17 PE/ST explants. Observe that miR-195 administration selectively increases the overall cTnI immunohistochemical signal (panel P and R). HH17 PE were dissected from >30 embryos, treated with the corresponding microRNA mimics and subsequently pooled to perform RNA isolation. On each case, three-to-five distinct biological replicates were subsequently tested by qPCR.