Thursday, August 2, 2007

Korean cloning fraud covered an accidental stem cell first, Harvard paper says

Harvard scientists have answered a question that lingered after Korean scientists retracted their fraudulent claim
that they had cloned the first human embryonic stem cells: Where did the stem cell line they created come from?

Kitai Kim, Dr. George Q. Daley (left) and their colleagues at Children's Hospital Boston and the Harvard Stem Cell Institute report today in Cell Stem Cell that the embryonic stem cells created by the Korean lab resulted not from somatic cell nuclear transfer, a technique in which a person's DNA is injected into a donor egg cell that has had its own DNA removed, but from parthenogenesis, the process of making an embryo from the donor egg alone.

Cells derived from parthenogenesis carry a distinct genetic fingerprint because they have a duplicate set of chromosomes from the egg. Most of the genetic sequences are identical, but some show differences from the donor egg. Investigators looking into the Korean claims last year said parthenogenesis could not explain these different patterns, the paper said.

Kim and Daley's group analyzed the cells further and found that the DNA differences were clustered at certain points, just as they are in experiments on parthenogenesis in mice.

The Koreans appear to have created the first human embryonic stem cells from a woman's egg alone, the paper says.

Daley's lab is studying parthenogenetic cells as another possible source of embryonic stem cells to treat disease.

A Children's Hospital interview with Daley is here.

Posted by Elizabeth Cooney at 12:40 PM

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