Two scientists report creating chromosomes

Harvard Medical School scientists say they have succeeded in creating the first man-made chromosomes, the genetic material that biologists track to discover how traits pass from one generation of organisms to the next.

Researcher Andrew Murray said Tuesday the man-made chromosomes - in yeast, not human, cells - could be used in basic gene-manipulation applications. But he warned its use in human genetic research was still limited. He said work he has done with Dr. Jack W. Szostak had succeeded in creating a chromosome in yeast, but he doubted it could be done with human chromosomes. The basic research could , however, lead to other findings about cell division, mutation, and birth defects, the researchers said.

The work has not been accepted without question. University of Washington Prof. Herschel L. Roman said he's unsure whether what the two produced is accurately described as a chromosome.