51.   When stimulated by an electric current, the nuclei of the fetal cells take up the foreign DNA.

52.   Wilmut said Thursday in a phone interview that he had not intended to clone an adult cell when he started the experiment, which originally dealt with fetal cells.

53.   But critics said a fetal cell accidentally could have been used since the sheep from which the cells to clone Dolly were taken was pregnant.

54.   Earlier this year, scientists in the United States succeeded in cloning a cow from fetal cells.

55.   Fetal cells can be present in the circulatory system of some animals during pregnancy, Wilmut said Monday.

56.   Fetal cells could be harmful.

57.   Scientists in the United States succeeded in cloning a cow from a fetal cells earlier this year.

58.   Scientists have been able to clone mammals from fetal cells for two decades.

59.   Scientists in the United States succeeded in cloning a cow from fetal cells earlier this year.

60.   The information is critical because scientists have been able to clone mammals from fetal cells for two decades.