Quantification of OFT lumen behavior.

<p>(A) OCT cross-sectional image of the OFT depicting the irregular shape of the lumen at mid-myocardial contraction (scale bar = 200 µm). (B) M-mode image obtained from cross-sectional image sequences along the yellow dashed line in (A), depicting the quantification of the time during which OFT walls were contracting (T_c), closed (T_closure), or expanding (T_e). Horizontal scale bar = 100 ms and vertical scale bar = 200 µm. (C) Calculated lumen area over the cardiac cycle for the 5 selected cross-sectional planes (L1 to L5, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0040869#pone-0040869-g001" target="_blank">Figure 1A</a>). (D) Fractional time over one cardiac cycle during which OFT walls were expanding (T_e), contracting (T_c) and closed (T_closure). t, time; T, cardiac period. Note that at the cross-sectional plane 5 (L5) only 5 out of 7 embryos showed lumen closure.