Figure 3. Smooth muscle cell specific deletion of Jag1 in the developing descending aorta is associated with decrease in vSMC markers and increase in sclerotome/cartilage markers.

A- Co-immunofluorescence of Jag1 (green) and αSMA (white) at E12.5 demonstrated that Jag1 is highly expressed in arteries and aorta branches (a1; arrow) and faintly detected in the heart (a2). B- Specific loss of Jag1 was confirmed in vSMC in the J1^SMKO (b1; bracket) but retained in endothelial cells (b1; arrowhead).H: heart; NT: neural tube; Scale Bars: 100µm. C–D- RNA deep sequencing analysis of J1^WT, J1^SMHTZ and J1^SMKO vSMC isolated from the DA at E14.5 showed variation of transcripts classified in “cytoskeleton and contractile genes” (C) and “skeleton and cartilage development” (D). Relative row count for each transcript is represented following a pseudo-color scale. E–G- qRT-PCR on Notch target genes (E), vSMC markers (F) and cartilage markers (G) was performed on isolated vSMCs in vitro to confirm differentially expressed genes identified by RNA deep sequencing in the litter#1. Expression level is represented relative to mean of the J1^WT samples +/− SEM. H–I- vSMC isolated from J1^WT and J1^SMKO DA were grown 10 days at high density and stained for alcian blue 8GX or alizarin red S (H). Protein level of JAG1 and chondro-osteogenic markers (COL2, SOX9, RUNX2, OSP and SCXA) was evaluated by Western blot. γTUBULIN was used as loading control (I).