Yin-Yang 1, a New Player in Early Heart Development
In this issue of Circulation Research, Gregoire et al1 report their discovery that Yin-Yang 1 (YY1) is a critical factor for the transition from cardiac progenitor to differentiated cardiomyocyte. The authors made clever use of currently available transcription factor (TF)-binding databases to perform a bioinformatic-based screen for factors regulating cardiac progenitor genes. They compared their data set of genes enriched in mouse embryonic stem (ES) cell–derived cardiac progenitor cells (CPCs) with freely available TF–binding databases. They initially screened 32 candidate TFs and, surprisingly, found that YY1, a known repressor of sarcomeric gene expression, is resident on many CPC genes.
Article, see p 900
The heart is the first organ to develop in the vertebrate embryo. Precardiogenic mesoderm is initially derived from anterior lateral plate mesoderm. Signals from surrounding tissues promote lateral plate to form cardiogenic mesoderm by inducing a cardiogenic transcriptional network. The cardiogenic mesoderm contains CPCs that differentiate into primitive cardiomyocytes. The transition from CPCs to cardiomyocytes is a critical developmental transition point that needs further study and is the focus of the study by Gregoire. Importantly, the cardiogenic developmental process can be mimicked …