University research could improve fertility treatments

Saturday, February 25, 2006

JEFFERSON CITY, Mo. -- University researchers have determined that disturbing a mouse embryo at a very early stage is likely to cause the pregnancy to fail -- a discovery that could lead to improvements in embryonic cell research and fertility treatments for animals and, perhaps, people.

The research led by Michael Roberts, a University of Missouri-Columbia animal sciences professor, was published last week in the journal Science.

The researchers found that the two cells in an early mouse embryo differ -- with one cell, which contains a protein called Cdx2, eventually forming the placenta and the other forming the fetus.

Scientists have known that frogs and insects form that way but there wasn't agreement on whether mammals did, Roberts said. The research found a pattern is established already in the egg.

Disrupting the Cdx2 protein's expression often prevented the placenta from forming properly, so the pregnancy likely would fail -- a finding that could help explain why cloning experiments often don't work, or take many tries, he said.

The cell could be disrupted by injecting something into it or by removing material from it.

Roberts said the finding could help researchers studying embryonic cells and those looking to improve fertility treatments in agriculture and, potentially, for people.

"In cloning, if you put in another nucleus and mess around removing things, chances are you're disturbing this pattern," Roberts said Friday. "You might get a messed-up placenta."

Roberts said the finding could help researchers studying embryonic cells and those looking to improve fertility treatments in agriculture and, potentially, for people.

Scientists need to be aware, he said, that they could be harming the chances for an embryo to develop by manipulating those early cells. Roberts said he hopes future research can help better identify which eggs or embryos stand the best chance of developing normally. He plans work with both mouse and cow embryos.

He said his research also could be helpful for scientists working to create stem cell lines for experiments, because blocking the expression of the Cdx2 protein, and hence the placenta's development, would ensure that the embryo could never become a baby.

"You could use the same technology to prevent a proper embryo forming," he said.

The findings come at a time when research on embryonic cells is a hot political topic in the state. A group is gathering signatures to place a measure on the November ballot that would protect any stem cell research allowed by the federal government.

The concern is over a process commonly called therapeutic cloning, in which the nucleus of an unfertilized egg is removed and replaced with the nucleus of another cell, such as a skin cell, with the resulting egg stimulated to divide. Those cells are then harvested, and researchers hope they could be used to help treat various diseases or injuries.

But opponents of the procedure say it amounts to destroying life at its earliest stages.

Roberts said he supports the ballot proposal and believes the technique has potential, though he said it will be years before scientists figure out how to make it work.

"There is great promise in embryonic stem cell research," he said. "I think it would be very foolish for Missouri to exclude themselves from high-class, ethically conducted research."

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