A–D. Expression of ANF mRNA in control (A, C) and FN-null (B, D) hearts. ANF is expressed in the atria, the left ventricle and to a limited extent, in the right ventricle. The expression patterns of ANF in control and FN-null embryos are comparable. Long arrow in A points to the proximal OFT, and short arrow – to the distal. E.
Cited 1 mRNA is confined to the left ventricle in control embryos. Inset in E shows the right side view. F. Expression of Cited 1 mRNA in FN-null heart is limited to the lower region of the straight heart tube, the presumptive left ventricle. E9.5 embryos are shown. A- atria, other abbreviations are as in Fig. 1. Scale bars in all figures are 100 μm unless otherwise stated.