CALVES CLONED FROM MILK CELLS

April 27, 1998

TOKYO (Yomiuri Shimbun) -- Scientists in a research laboratory in Tomakomai, Hokkaido, have succeeded in cloning two calves from mammary gland cells extracted from cow's milk, Snow Brand Milk Products Co. announced Monday.

One of the calves was delivered by cesarean section last Tuesday, and the other naturally the following day. The first calf weighted 44 kilograms, and the second 45 kilograms, both within the average weight range for newborn calves. The calves, whcih are both female, and their mothers are healthy, according to the Tokyo-based company.

This is believed the first time that calves ave been cloned from mammary gland cells obtained from milk. The development is believed to be a big boost to the commercial application of a technique that will enable farmers to increase the number of high milk-yielding cows without harming the parent animals.

Nearly 60 cows and bulls have been cloned in Japan using cells removed directly from the body, but direct cell removal subjects donor cows to risk bacterial infection, according to experts.

In May, the researches at the Tomakomai laboratory extracted mammary gland cells from milk prdoucted by a Holstein cow after it gave birth. After cultivating the cells for two months, the researchers transplanted the nuclei of the cells into unfertilized eggs. The zygotes were implanted into the wombs of several cows kept at the laboratory as surrogate mothers. Some of them had miscarriages, but two continued to carry fetuses to full-term.