Epiblastderived

Epiblast-derived, in embryology and stem cell biology, refers to cells, tissues, or cell lines that originate from the epiblast, the outer layer of the bilaminar germ disk in early development. The epiblast lies above the hypoblast and contains pluripotent cells that will form the embryo proper.

During gastrulation, epiblast cells undergo extensive movements and become the three germ layers: ectoderm, mesoderm, and endoderm. In many mammalian embryos, the epiblast also contributes to extraembryonic structures such as the amnion. Thus, epiblast-derived cells are central to the formation of most tissues of the mature organism, while some lineages arise from adjacent or subsequent lineages.

In stem cell research, epiblast-derived stem cells (EpiSCs) describe pluripotent cells isolated from post-implantation epiblasts. EpiSCs represent a primed state of pluripotency, distinct from the naive state associated with traditional embryonic stem cells (ESCs) derived from the inner cell mass of blastocysts. Culture systems for EpiSCs typically rely on signaling cues such as FGF and Activin/Nodal, and human embryonic stem cells often resemble this primed state rather than the naive state seen in mouse ESCs.

Epiblast-derived cells are used to study early development, lineage specification, and transitions between naive and primed pluripotency, with implications for disease modeling and regenerative medicine. The term should not be confused with cells derived from hypoblast or trophoblast lineages, which contribute to other components of the embryo and placenta.