The question asked whether a parthenote, which only contained pluripotent and not totipotent cells
and was therefore incapable of developing into a human being, was included in the term "human embryo" under Article 6(2)(c) of the Directive.
Sacrococcygeal teratoma arises from the totipotent cells
of the caudal cell mass.
In contrast to a fertilized human ovum, which gives rise to totipotent cells
and possesses the inherent capacity to develop into human beings given the right environment, chemically activated oocytes or "parthenotes" arc pluripotent and, therefore, incapable of ultimately developing into human beings.
Two major advances in stem cell research occurring in 2013 and 2014 pave the way for eventual mitochondrial replacement therapy: (1) successful cloning of a human to the blastocyst stage of development, and (2) transformation of specialized mouse, somatic cells into totipotent cells
. Two mitochondrial replacement therapy scenarios would result in genetic modification of an individual's germ line, and one of these involves human reproductive cloning.
Alkaline phosphatase (AP) activity is high in totipotent cells
in vivo and in vitro, but reduced or lost upon differentiation.
Since teratomas arise from embryonic totipotent cells
that theoretically arise from Henson's node and migrate caudally to rest in the coccyx, many advocate for coccygectomy when a sacrococcygeal teratoma is diagnosed, whether at birth or in an adult [6,7,9,14,15].
Immature embryos are highly regenerative as they contain embryogenic totipotent cells
(Zale et al., 2004).
Specifically, they have the characteristics of totipotent cells
: a primitive state never before obtained in a laboratory.
This includes totipotent cells
(which appear after fusion of gametes) and unfertilized ova into which a cell nucleus has been inserted or whose division has been stimulated by parthenogenesis and the blastocyte.
Pluripotent stem cells are the descendants of totipotent cells
and can differentiate into nearly all cells.
The therapeutic benefit of these totipotent cells
is heralded by the moral and ethical concerns as extracting stem cells from embryo destroys the embryo itself.