Danes, Australians collaborate on 'handmade clones'

Australian and Danish scientists have developed a breakthrough new technique to clone animals they term "handmade cloning."

The method may enable cloning of elite agricultural animals to become commercially viable, according to the researchers.

The new method, reported in New Scientist this week, relies on the use of an ultra-fine blade to cut manually egg cells in half. The cell membranes snap back to enclose each half of the cell. The half of the egg that contains the nucleus is discarded, and the other half of the cell, or cytoplast, is fused using an electric current with an adult cell. The resulting cell is then fused again with a second cytoplast. The fused cell is then allowed to develop into a blastocyst before being implanted.

In the traditional nuclear fusion cloning approach developed by Ian Wilmut and colleagues, the nucleus of the egg is sucked out using a micromanipulator and replaced with the nucleus from the donor cell.

Dr Ian Lewis, the Australian scientist credited with co-developing the technique, said that the advantages of handmade cloning included the substantially cheaper cost and apparent efficiency of the process. While a micromanipulator is a sophisticated piece of equipment costing $50-100,000 and requiring a great deal of skill to use, the blade used in his method costs a mere $15 and the procedure is very simple.

And according to Lewis, the efficiency of the new cloning process is good.

"It provides at least as good outcomes as the present methods, and is probably three times as efficient," he said. "We're quite excited about it."

Lewis, who is the manager of technology development at Genetics Australia dairy cooperative and programme leader at the new CRC for Innovative Dairy Products, co-developed the method with Danish scientist Gabor Vajta from the Danish Institute of Agricultural Sciences.

Frustrated at the inefficiencies of traditional cloning technology, Lewis decided to combine a number of approaches he had worked with in the past, working nights and weekends to develop his idea.

"When I got proof of principle, I brought in Gabor to develop the nuts and bolts of the technology," he said. Vajta and Lewis had worked together in the past at the Monash Institute of Reproduction and Development.

"It's been a really nice collaboration," Lewis said.

Lewis said that while the new method is still very much in the research phase, a calf has already been born at Genetics Australia, with another on the way there and three more due in Denmark. "Those animals were born from a limited number of transfers. We were just testing out the process, now we can make a lot more," he said.

He warned, however, that it would take a number of years before cloning of cattle and other livestock became commercially viable, noting that consumer acceptance, further improvement to the technology and IP issues were still to be dealt with.

Consumer and regulatory acceptance of products from cloned animals would be important, he explained, as milk manufacturers were concerned about losing their market. But with Japan deciding this week to allow human consumption of beef and milk from cloned cattle, Lewis said the commercial prospects were looking more encouraging.

"It's important that we keep researching it so that we're ready to go," he said.

Meanwhile, Lewis said that the powerful new technology was being adopted already by cloning labs.

While patents have been filed on the method, they don't exclude the existing cloning patents, according to Lewis.

"We still have to work within the framework of the original cloning patents. But it puts us in the position of being able to negotiate," he said.

Lewis said the research would be published in the journal Biology of Reproduction before the end of the year.