Figure 2. Nfatc1^cre/+ line specifically labels endocardial cells.

A The percentage of Nfatc1-derived cells within total endothelial cells in embryonic tissues during embryogenesis measured by flow cytometry for Tomato, CD31, CD41 and CD45 in Nfatc1^cre/+; Rosa26^{Tomato reporter/+} embryos. Tomato-positive cells are identified in the CD31⁺ CD41⁻ CD45⁻ pure endocardial cells in heart tissue at E9.5. CD41⁺ fraction was excluded as CD31 is expressed in a subset of CD41⁺ circulating progenitors at this stage. Data represent mean ± SE.

B. Representative histogram of Nfatc1-lineage-labeled cells within CD31⁺ CD45⁻ endothelial (endocardial) cells in the heart, yolk-sac, and caudal half from Nfatc1^cre/+; Rosa25^{Tomato reporter/+} at E18.5.

C. The percentage of Nfatc1-derived cells within total endothelial cells in embryonic tissues during embryogenesis measured by flow cytometry for Tomato, CD31, and CD45 in Nfatc1^cre/+; Rosa26^{Tomato reporter/+} embryos. Tomato-positive cells are identified in the CD31⁺ CD45⁻ pure endocardial cells in heart tissue. Liver endocardial cells, known to be partially derived from endocardial cells, are also Tomato-positive. Data represent mean ± SE.