Mef2c binds to the Crtl1 Promoter in the developing heart.

<p>(A) Immunoblot for Mef2c protein. Lane 1, Mef2c binding to control Mef2 consensus sites from the muscle creatine kinase gene. Lane 2, negative control oligo with mutated Mef2 sites fails to bind to Mef2c. Lanes 3 and 5, Mef2c interacts with the Mef2 consensus sites in the Crtl1 promoter region at −913 to −923 (Site 1, Lane 3) and at −698 to −707 (Site 2, Lane 5). Lanes 4 and 6, mutation of the Mef2 consensus sites in the Crtl1 promoter region blocks Mef2 binding at both consensus sites. (B) Mef2c and Sox9 bind the Crtl1 Promoter <i>in </i><i>vivo</i>. Chromatin Immunoprecipitation (ChIP) was performed using embryonic hearts stage ED10.5–11.0. PCR of the DNA input, Mef2c immunoprecipitate, and IgG control precipitate was performed using primers flanking both Mef2 consensus sites of the Crtl1 promoter. For the Sox9 ChIP, the initial DNA input, Sox9 immunoprecipitate, and IgG control precipitate were PCR amplified using primers specific for the Sox9 consensus site on the Crtl1 promoter.