Totipotency
Totipotency (from Latin totus "whole" and Latin potentia "ability, strength") describes the ability to form the whole.
In cell biology , cells are called totipotent if they have the ability to form a complete or independent organism . For example, if they can still develop complete individuals in a suitable environment, such as the uterus . For the development of mammals, including humans, it is assumed that embryonic cells are totipotent up to the 8-cell stage at the latest. In experiments with primates, however, it has so far only been possible to produce animals from individual cells of the four-cell stage in a few cases. The blastocyst , consisting of an inner cell layer ( embryoblast ) and an outer cell layer ( trophoblast ), is a young cluster of cells consisting of a few hundred cells , the inner cells of which are only pluripotent due to the loss of development potential .
The embryological concept of totipotency must be differentiated from the cell biological term totipotency. It describes the phenomenon that embryos are able to form a whole again even after parts have been removed or after the embryo has been divided (embryo splitting). A classic example of this is the division of the germinal disc in the regular multiple formation of certain species.
In biology was in the 1960s (based on callus cultures of Weinraute ) proof of Omnipotenz undifferentiated cells in the area of secondary metabolism out.
See also
Individual evidence
- ↑ Franz-Christian Czygan: Possibilities for the production of medicinal substances through plant tissue cultures. In: Planta med. Supplement 1975, pp. 169-185.