Researchers report defects in cloned mice

By Jennifer Hiller
Advertiser Education Writer

New research by University of Hawai'i scientists indicates that cloned mice have unpredictable abnormalities, buttressing their arguments that similar cloning methods should not be considered for humans.

In articles published in the periodicals Science and Genesis, Ryuzo Yanagimachi, professor of anatomy and reproductive biology and the director of the Center for Biogenesis Research, outlines the abnormalities and how they may be caused by a nongenetic modification of the DNA.

The papers also show that using embryonic stem cells for cloning results in numerous complications.

The stem cells have the ability to develop into any type of body cell and many scientists believe that they hold the key to medical treatments and cures.

But even if a clone from a stem cell survives and appears healthy, there is no way to tell whether there will be physical or mental deformities later — or which genes caused the problems, said Stefan Moisyadi, a researcher at the Institute of Biogenesis Research.

"The clones all have the original genes. Everything is there, but not all the genes are expressed the way they should be expressed," Moisyadi said. "Some of the mice don't make it full term or die after birth. The genes necessary for them to function aren't there."

The offspring of cloned mice do not have the same genetic problems, indicating that reproduction resets the DNA pattern, Moisyadi said.

Yanagimachi made international headlines in 1997 with a cloned mouse named Cumulina. Although she was not the world's first cloned animal, Cumulina stunned the scientific world because she was the first of more than 50 mice to be cloned through three generations.