MOLECULAR ANALYSIS OF NORMAL AND HYPOPLASTIC CHICK EMBRYONIC VENTRICLES

Abstract

The term hypoplastic left heart syndrome (HLHS), describes a spectrum of cardiac abnormalities characterized by marked hypoplasia of the left ventricle We employed the Affymetrix gene chip technology to gain a better insight into molecular characteristics of embryonic and early fetal myocardial differentiation. RNA isolated from normal left (LV) and right (RV) chick ventricles on ED 6, 8, and 10 was checked for quality using Agilent capillary electrophoresis, and after cDNA synthesis hybridized on the chick whole genome chip. In addition, RNA from E8 LV and RV of hearts with developed left ventricular hypoplasia after left atrial ligation was treated in the same fashion. Comparisons were made of LV vs. RV at different stages of development, as well as between control and treated groups. Interestingly, the number of genes upregulated in the LV was much lower than those higher in the RV. This suggests that differentiation of the working myocardium lies more in a restriction of gene expression program, with specific upregulation of select few genes, such as MYH11, MYR8, GBJ6:gap junction protein, beta 6, others from contractile proteins/myocyte differentiation group of genes, FGF13, NF1 from proliferation/Growth factors genes. With this data we want to explain roles and involvement of some genes of the ventricular myocardium at different stages of development as well as their connection with congenital heart disease.