For the first time, a Harvard science team led by Korean scientists proved that Hwang’s NT-1 stem cell was achieved by parthenogenesis, not somatic stem cell transfer. Hwang has maintained that the stem cell was created through the latter procedure.
In the September issue of the journal Cell Stem Cell, a team of scientists led by Kim Kitai of the Harvard Stem Cell Institute, said that they developed a method of distinguishing whether or not embryonic stem cells were achieved by parthenogenesis or somatic cell nuclear transfer.
Parthenogenesis refers to the development of an embryo that has not been fertilized by a male. Although this occurs naturally in some species such as lower plants and invertebrates, it can also occur by artificially activating oocytes without fertilization. Somatic cell nuclear transfer refers to the growing of a cell by removing the nucleus from a regular, or somatic cell. The nucleus is then injected into an ovum, which does not then need to be fertilized.
According to the article, the scientists used DNA fingerprint analysis of nuclear donor cells and analysis of gene patterns among other things, to prove which stem cells were from parthenogenesis and which from somatic cell nuclear transfer.
Although there had been previous successes in somatic cell nuclear transfer, such as Dolly the sheep, Hwang made a sensation in 2004 when he said that he achieved the process with a human embryo. His research results were published in the journal Science, but were later retracted because of research misconduct and forged data that was used in the paper. Hwang was eventually fired from his position as professor at Seoul National University.
When prosecutors began Hwang’s case two years ago, they focused only on fund embezzlement and bioethics violations, saying it was up to the science community to figure out the “truth” behind the stem cells.
According to the September article in Cell Stem Cell, Hwang did create the first human stem cell line, but by parthenogenesis. This finding coincided with that of the Seoul National University Investigation Committee last year.
By Wohn Dong-hee
Staff Writer for JoongAng Daily