A differentiation program induced by bone morphogenetic proteins 4 and 7 in endodermal epithelial cells provides the molecular basis for efficient nutrient transport by the chicken yolk sac.

The mammalian yolk sac provides nutrients for the growing fetus during critical early developmental processes such as neural tube closure, which precedes the functional maturation of the placenta. In contrast, oviparous species such as the chicken rely solely on the yolk sac for transfer of nutrients from the yolk to the developing embryo. However, the molecular mechanisms that provide the yolk sac with nutrient transfer competence remain poorly understood.

Pubmed ID: 31691430