Study Shows Hwangs Cells Were Unisexual Reproduction
By Kim Tae-gyu
Staff Reporter
A team of researchers at Harvard Medical School claim the stem cell line created by Korea's disgraced veterinarian Hwang Woo-suk was generated via unisexual reproduction, not cloning.
The team, including Korean researcher Kim Ki-tai, wrote an article in which they allege the stem cell line, known as NT-1, was not a clone. Cell Stem Cell featured the piece today.
If it is widely accepted by scientists, the standing of Hwang is expected to further contract because he has argued that NT-1 is indeed a clone, which demonstrated his expertise in cloning.
Kim and his associates made mouse stem cells both through cloning and unisexual reproduction, respectively with the aim of analyzing their differences.
Looking at the genetic signatures, specific to each method, they found that NT-1 was identical to the pattern of unisexual reproduction.
With such a comparison, the Harvard team concluded the disputed Korean stem cell line came from an unfertilized egg and was not cloned.
The experiments are likely to make many embryologists believe NT-1 is not a clone line.
``This is the first systematic research with comprehensive genetic analysis aimed at distinguishing the type of human embryo that stem cells come from,'' Prof. Park Se-pill at Jeju National University said.
``A majority of scientists are projected to side with the paper. It will not weed out all controversy, though. We need more complete experiments,'' said Park who extracted stem cells from embryos in 2000 for the third time in the world.
In response, Hwang's team downplayed the paper.
``We have yet to look into the paper but as far as we know, it has no new ideas or experimental work,'' said a doctor who works for Hwang and wanted to identified by just his surname Chung.
``The controversies are likely to continue down the road and I still believe NT-1 is a clone. More experiments are necessary to identify the origin of the stem cell line,'' he said.
Hwang basked in a global reputation in early 2004 when the Science journal documented his article on NT-1, which was believed to be the world's first cloned human embryonic stem cell line.
The next year, Science printed another paper from Hwang on patient-specific stem cells, which many hailed as a help to cure hard-to-treat diseases such as diabetes or Alzheimer's.
The papers were found to be based on fabricated data and the peer-reviewed Science retracted both.
While admitting some faults, however, Hwang has contended that NT-1 is a genuine clone, not spawned through parthenogenesis.
voc200@koreatimes.co.kr