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A Nature Reports Stem Cell survey of researchers shows that though most grantees are using stem cell lines eligible for funding under federal law, they are using more lines that are not
Unfertilized eggs have long been the limiting resource for attempts to make genetically tailored human embryonic stem cells. If a new technique for cloning mice from fertilized eggs works in humans, they might not be necessary.
Findings that fertilized eggs can be used to clone mice raise an old question: how can a single cell manipulate DNA to support an entire organism's development?