Department of Anatomy, University of California, San Francisco, California 94143, USA. zena@itsa.ucsf.edu
Fetal nutrition depends on the placenta, and specifically, the branching of a layer of placental trophoblast cells that sits between the maternal blood and fetal blood vessels. The discovery that expression of the transcription factor Gcm1 in trophoblast stem cells regulates branching of this specialized epithelium offers new insights into a process whose pivotal features have been generally obscure.
