Sodium-calcium exchanger is initially expressed in a heart-restricted pattern within the early mouse embryo

Although the sodium-calcium exchanger (NCX1) is encoded by a single gene, it is widely expressed in both fetal and adult tissues and functions in many diverse physiological processes to maintain intracellular calcium homeostasis. In order to determine whether NCX1 is also ubiquitously expressed in the early mouse embryo, in situ hybridization and RT-PCR were used to determine the spacio-temporal expression of NCX1. Our results indicate that NCX1 expression is present within the 7.75-8.0 dpc cardiogenic plate before the first heartbeat, and that NCX1 is initially expressed in a heart-restricted pattern within the early mouse embryo. However, in more developed embryos (11.0 dpc and older) NCX1 is expressed in other tissues.