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AN ATTEMPT to repeat controversial experiments in which human cells were
fused with cows’ eggs has landed a team of Japanese researchers in serious
trouble. The Ministry of Education is now investigating the project as a breach
of its ethical guidelines on human cloning.

The research was carried out a year ago by Setsuo Iwasaki’s team at the Tokyo
University of Agriculture and Technology. Following in the footsteps of the
company Advanced Cell Technology in Worcester, Massachusetts
(New Å®ÉúСÊÓƵ, 11 July 1998, p 4 and
21 November 1998, p 14),
Iwasaki removed the chromosomes from 27 cows’ eggs, which he then fused with human
cells—in this case cancerous blood cells cultured from leukaemia
patients.

When the Yomiuri newspaper ran the story of Iwasaki’s experiments
last week, he told the paper that he hoped to isolate embryonic stem
cells—from which all the body’s tissues eventually develop. This would
have meant culturing the hybrid embryo for about five days, until it formed a
hollow ball of cells called a blastocyst. However, most of the embryos did not
develop and none underwent more than three cycles of cell division.

Iwasaki’s work has been greeted with widespread concern in Japan, where
guidelines designed to prevent human cloning bar researchers in universities and
other public research labs from fusing human cells with eggs. He had not cleared
the experiment with his university believing the guidelines did not apply to
cows’ eggs. The university says that future proposals will be rigorously
screened by a new ethics committee.