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. Author manuscript; available in PMC: 2016 May 16.
Published in final edited form as: Mech Dev. 2015 Jan 6;136:123–132. doi: 10.1016/j.mod.2014.12.005

Fig. 2.

Fig. 2

Fibulin-1 deficient embryos display hypercellular OFT cushions and blood cell accumulation in OFT cushions at E9.5. (A and B) H&E stained E9.5 sections of proximal OFT cushions from wild type and Fbln1 null embryos, respectively. Note the abundant cells present in the cushion of the Fbln1 null section compared to the wild type. (C) shows a higher magnification of boxed region in (A). Note endothelial cells (black arrows) lining the OFT lumen (L) and the absence of mesenchymal cells in the wild type cushion (C). (D) shows higher magnification view of boxed region in (B) showing endothelial cells (black arrows) lining the lumen of the OFT of a Fbln1 null. Note the presence of mesenchymal cells (white arrowheads) and blood cells (black arrowheads) in the proximal cardiac jelly of the Fbln1 null. (E and F) show E9.5 wild type and Fbln1 null proximal OFT cushions stained with Benzidine (brown) to label hemoglobin-producing cells. Sections were counterstained briefly with Eosin. Inset in (E) shows higher magnification of hemoglobin positive cells located normally within the lumen of wild type proximal OFT cushions. Inset in (F) shows higher magnification of hemoglobin positive cells in the cardiac jelly region of Fbln1 null proximal OFT cushions. All sections are sagittal. (G) and (H) show quantification of mesenchymal and blood cells, respectively, present in wild type and Fbln1 null proximal OFT cushions. (G) Fbln1 nulls show a 354% increase (p = 0.0002) in mesenchymal cells present in the cushions. Cell counts were obtained from 54 sections from four wild type embryos and 54 sections from four Fbln1 null embryos. Pound (#) in (H) indicates that no blood cells were detected in wild type proximal cushions at E9.5. (I) and (J) show AMIRA 3D reconstructions of wild type and Fbln1 null proximal OFT cushions at E9.5. (I) 3D reconstruction of wild type shows endocardial cell content but little mesenchymal cell content (blue) and no blood cell content in the cushion. (J) 3D reconstruction of Fbln1 null shows an increase in mesenchymal cell content (blue) and the presence of blood cells (red) in the proximal cushions. C, proximal OFT cushions; L, lumen of OFT.