Remember human embryonic stem (hES) cells? We don't hear much about them anymore. So I was surprised to see an application of the controversial cells to grow human embryo-like structures in a recent issue of Nature.
Human embryonic stem cells are not, and have never been, taken from human embryos. Instead, they're grown in laboratory glassware from cells that are sampled from the inner cell mass. The "icm" is the stage when the prenatal human is a smear of cells hugging the interior of a hollow ball of cells, the blastocyst. The icm expands and contorts, layering itself into embryohood, as the blastocyst gives rise to the nurturing extra-embryonic membranes.
In 2009 the National Institutes of Health issued guidelines forbidding researchers from using government funds to derive new hES cells, but the agency provides nearly 500 already-existing hES cell lines. They represent dozens of inherited diseases, from cancers to neurological conditions to connective tissue disorders – quite an eclectic list.
To continue reading, go to my blog DNA Science, where this post first appeared.