Totipotent stem cell can produce all types of cells that make up the body, as well as all types of cells that make up extra-embryonic tissues, such as the placenta.
An example of a totipotent cell is a zygote – a cell that arose as a result of fertilization.
What are totipotent stem cells and how long do they maintain totipotency?
Totipotent stem cells are unique cells that function not only in a particular place in the body but also at a strictly defined time. In the human body, totipotent cells exist only at the zygote stage.
A fertilized egg is totipotent – it has unlimited potential in the sense that, under appropriate conditions it alone is enough for the formation and development of a normal fetus.
In the first hours after fertilization, it divides with the formation of identical totipotent cells, and any of them, when implanted in the woman’s uterus, can give rise to fetal development. During the first divisions of the zygote (at the “morula” stage), these cells maintain totipotency.
About four days after fertilization, when several cycles of cell division take place, totipotent cells begin to differentiate with the formation of a spherical structure called “the blastocyst”, and become pluripotent.
Totipotent stem cells and ESCs
The totipotent cell gives rise to embryonic, extraembryonic and trophic ectodermal tissues.
Totipotent cells of the embryo are also called embryonic stem cells (ESC). Embryonic stem cells are isolated from embryos from the blastocyst stage.
Despite the fact that they can differentiate into all types of cells of our body, their use raises serious bioethical issues, since their production entails the destruction of the embryo.
Part of the society is negatively inclined towards the use of ESCs in medicine and science, even though the ESC donors are embryos that remained unclaimed during the in vitro fertilization procedure, and there is a technology for collecting single cells, used, for example, for early embryonic diagnosis and not causing the death of the embryo.