pluripotency

Pluripotency is the biological property of a cell that enables it to differentiate into all cell types of the three germ layers—ectoderm, mesoderm, and endoderm—while generally being unable to form extraembryonic tissues such as the placenta. Pluripotent cells can give rise to any cell type in the body but cannot generate a complete organism on their own.

Most pluripotent cells arise in development from the inner cell mass of the mammalian blastocyst, giving rise to embryonic stem cells (ESCs). Pluripotency can also be achieved by reprogramming adult somatic cells into induced pluripotent stem cells (iPSCs) through expression of transcription factors such as OCT4, SOX2, KLF4, and MYC. Human and mouse pluripotent cells exhibit different states and growth requirements, often maintained in culture with specific signaling factors to preserve their undifferentiated status.

Pluripotency is tested by functional assays and molecular markers. In vitro differentiation can show the ability to form derivatives of all three germ layers; teratoma formation in vivo demonstrates broad developmental potential. Pluripotent cells express core transcription factors like OCT4, SOX2, and NANOG, among others.

Applications include basic research, disease modeling, drug screening, and regenerative medicine. Induced pluripotent cells offer a patient-specific source of material, but risks include ethical concerns related to embryo use (primarily for ESCs), potential tumorigenicity, genetic and epigenetic abnormalities, and immune compatibility challenges. Ongoing work seeks to improve safety, genomic stability, and directed differentiation.