totipotenta

Totipotenta refers to the developmental potential of a cell to form all the cell types in an organism, including both embryonic and extraembryonic tissues such as the placenta. In animals, totipotent cells are present only in the earliest stages of development and their descendants lose totipotency as differentiation proceeds.

In mammals, the zygote and the initial cleavage-stage cells (often described as the 4- to 8-cell stage, and sometimes the morula) are considered totipotent. These cells can, in principle, give rise to the entire organism as well as the supporting placental tissues. As development proceeds, cells transition to pluripotency, which allows formation of all embryonic lineages but not the placenta or other extraembryonic structures. Pluripotent cells thus form the embryo proper but not the entire organism on their own.

In plants, totipotency is more widespread. Many plant cells can revert to a meristem-like state and generate complete organs or whole plants from a single cell, enabling common techniques in plant tissue culture and somatic embryogenesis.

Applications and research context often distinguish totipotent from pluripotent cells. Totipotency is central to discussions of early embryology, cloning, and regenerative medicine, though true totipotent cells are fleeting in natural development. In laboratory settings, scientists explore totipotent-like states and reprogramming strategies to extend developmental potential, while recognizing the precise regulatory and ethical considerations involved.