The experiments that created what some have called the first cloned human embryo began in 1990 with an unremarkable event: A graduate student simply ran out of supplies.
The student, who now works as a researcher in Norway, was transferring the nuclei of rabbit cells into rabbit eggs in a University of Massachusetts lab run by Jim Robl, a professor of veterinary and animal science who received his Ph.D. from the University of Illinois.
“One day, he didn’t have any donor cells, and he didn’t know what to do for donor cells,” Robl said. “He took a swab of his own cheek, took some cells and injected them into rabbit eggs. I didn’t find out about it until after it was done.”
To the researchers’ surprise, some of the cells started to divide, just as they would in a healthy embryo.
“They continued to grow, and we started to get nervous,” Robl said. “I didn’t know if these were human embryos.”
In 1996, a researcher in the lab, Jose Cibelli, took 52 cow eggs and removed their nuclei, which is where the genetic material lies.
Each cow egg had contained half the genes needed to create an offspring–in the barnyard, the other half would have been delivered inside a sperm from a bull.
Cibelli then scraped some cells from the inside of his cheek and began driving the nucleus of the human cell into an empty cow egg with a subtle jolt of electricity.
The idea was to create a new nucleus not from two halves–an egg and a sperm–but from a single whole–one cheek cell. If it worked, the cell would, with a small but important distinction, contain only the genetic material of the donor, making it a clone.
Eventually, most of the eggs stopped dividing. One, however, continued, and was kept alive in a culture for three weeks, Robl said.
That one small exception to the genetic purity of the embryo is a crucial one: Even when the nucleus of the cow egg is taken out, the cell retains some genetic material in its mitochondrion. That means the dividing cells contained a mix of mostly Cibelli’s DNA with a dash of bovine DNA.
Robl and his partners in a business that holds the patent on the technique, Advanced Cell Technology Inc., say they made their recent announcement because they wanted to begin a debate on the ethics of their procedure.
“The concern was that if you put a bunch of money into it and you get down the road and everybody is horrified by it,” Robl said, “then you have wasted time and money.”
