Not exact matches
► The U.S. National Institutes of Health (NIH) has put funding on hold for experiments that involve «mixing
human stem cells into
very early animal
embryos and letting them develop» while it «reconsiders its rules» for this type of research, Gretchen Vogel reported Wednesday.
The ability to keep
human embryos developing in the lab for almost 2 weeks — achieved for the first time this year — should provide new insights into
very early human development, and generate debate on whether ethical limits on studying
embryos in culture should be extended.
This is already widely used to preserve certain kinds of mammalian cells, including blood cells, and will even preserve
very early mammalian
embryos, including
humans, when the cells are all similar and have not yet taken specific functions.
Researchers at Karolinska Institutet have identified cell surface markers specific for the
very earliest stem cells in the
human embryo.
If you believe, for example, that granulosa cells and other
very early features of ovarian ecology set up the polarities that ultimately determine the quality of a
human egg, as Albertini does, then certain techniques widely used in IVF may be subtly perturbing the
very mechanisms that eggs use to establish a plan to build an
embryo and maximize the chances that it will develop properly.
The application is on hold, the agency has told him, as NIH reconsiders its rules for the kind of experiments he wants to do: mixing
human stem cells into
very early animal
embryos and letting them develop, a strategy that could produce tissues or organs for transplantation.
But its September decision bars experiments in which
human stem cells are injected into
very early embryos.
Belmonte uses
very early - stage pig
embryos, whose biological signals are capable of turning
human stem cells into the «perfect
human organs» he's after.
Although it is known that gross chromosomal abnormalities are remarkably common in
early human embryos, our understanding of
early embryonic somatic mutations is
very limited.