The combination of jellyfish gene and monkey embryo recently brought UW-Madison researchers one step closer to understanding the workings of human pregnancy.
Scientists at the UW Primate Research Center successfully inserted a jellyfish gene into the fertilized eggs of rhesus monkeys, producing “transgenic” placentas in which the inserted gene functions as it does in its natural environment.
“This will help us understand the role specific genes play in normal placenta development,” said Dr. Thaddeus Golos, UW associate professor of obstetrics and gynecology and the leader of the study.
The experiment will also help scientists understand the role genes play in pregnancy disorders.
The placenta is key to a successful pregnancy because it is the first fetal organ to develop. It also provides nourishment to and removes wastes from the fetus throughout the pregnancy.
Scientists attribute conditions such as infertility, recurrent spontaneous miscarriages and low birth weight to problems with the placenta.
“If you don’t have a healthy placenta, you don’t have a healthy pregnancy,” Golos said.
Researchers used the jellyfish gene in the study because it emits a green glow when exposed to ultraviolet light. This property allows scientists to view the cells of their experiment without killing them.
“We chose the green florescent protein as a reporter gene,” he said. “It shows if [the] gene transfer has been successful.”
The rhesus monkey’s genetic resemblance to humans made it a natural subject choice for the scientists. The genetic makeup of a rhesus monkey differs from a human’s only slightly. The monkey is also similar to humans in reproduction, early development and pregnancy.
This experiment is the first in which a gene transferred into a monkey embryo has been functional throughout a pregnancy to a live birth.
The two monkeys born in the experiment, however, did not carry the jellyfish gene, despite the present and functioning gene researchers found in the placentas.
Golos said the technique could produce monkeys that carry the gene, but that the accomplishment of the gene remaining functional throughout embryonic development was sufficient to provide future research on pregnancy.
The UW experiment is similar to a study conducted at the Oregon Regional Primate Research Center in January. Researchers there reported the birth of a monkey with a jellyfish gene present. However, the gene was unable to function in the monkey the way it would in a jellyfish.
The use of monkeys in transgenic research shows the possibility of future human gene therapy, although this issue is somewhat controversial.
Dr. R. Alta Charo, UW professor of law and medicine ethics, said many people fear genetic engineering and biotechnology.
“They are concerned that the human race is unable or unready to exercise the power it offers,” she said.
But Golos said his team of researchers was very cautious in the transgenic study.
“The focus is on the needs of maternal-fetal health,” he said. “This is the need we’re responding to.”
Dr. Waclaw T. Szybalski, professor of oncology, said the researchers were conservative in their conduct.
“They were able to transform the placenta and not the animal,” he said.
Szybalski, as well as many other scientists, sees the future of science as helpful, not harmful, to people.
“In general, there is great advantage to do all kinds of genetic experiments,” he said. “That’s where the hope for humanity lies.”
He said the transgenic research is important because it is an additional tool in the process of genetic study.
Golos said plans for the future of the study include testing hypotheses about the placenta with the information derived from the research.
“There are lots of hypotheses, but not much hard data,” he said.
Despite the value associated with particular studies, Charo said ethical issues always arise from choices about how and what to genetically engineer.
“Technology is like the bee,” she said. “It brings both the honey and the sting.”