Mouse cloned from a single drop of blood - June 28, 2013

A Japanese research group at the Riken BioResource Center succeeded in cloning a mouse using nothing more than a single drop of blood extracted from a donor mouse’s tail, according to BBC

and iO9.

The cloned mouse possessed the same genetic makeup as its donor. Not only did it live a normal lifespan, it was also capable of producing offspring.

Scientists at another institute have reportedly produced 600 perfect genetic duplicates of a single mouse after 25 sequential rounds of cloning.

Mice have previously been cloned from a variety of sources, including white blood cells from the donor’s liver, bone marrow, and lymph nodes. Taking genetic material from these sources, however, requires that the animal be put to sleep. This has proven difficult in certain situations, such as when there is only one living individual of a particular species remaining, or when the available specimens possess variable strains of genetic material.

Alternate donor cells

Led by Atsuo Ogura of Riken BioResource Center in Tsukaba, the Japanese scientists, whose aim was to discover an alternate source of donor cells for the purposes of cloning prized strains of laboratory mice, investigated circulating blood cells. After extracting blood from a donor mouse’s tail, white blood cells – or leukocytes – were isolated. The nuclei from these cells were then used in a cloning experiment.

The cloning experiment involved a technique known as “somatic cell nuclear transfer”, in which an adult body cell’s nucleus is transferred into an unfertilized egg that has had its nucleus removed. This was the same technique utilized by Scotland’s Roslin Institute to produce the world’s first cloned animal, Dolly the sheep.

After successfully cloning a mouse, the scientists believe they have “demonstrated for the first time that mice could be cloned using the nuclei of peripheral blood cells”.

No more animal sacrifices

This breakthrough means animals will no longer have to be euthanized when their cells are extracted for cloning purposes.

“These cells could be used for cloning immediately after collection and no donor animals need to be euthanised,” said the team. “This technique would be applicable for generating genetic copies of invaluable strains of mice, which cannot be preserved by other assisted reproductive techniques such as conventional in vitro fertilisation or intracytoplasmic sperm injection.”

The researchers aim to test the technique with larger animals. If successful, they hope to use it for the mass-production of farm animals.

This is also significant development where the effort to save endangered animals is concerned.

“The efficiency of cloning from these cell types was very good, suggesting that even a small drop of blood will contain sufficient numbers,” said Professor Robin Lovell-Badge of London’s MRC National Institute of Medical Research. “This is helpful if the intention is to use cloning to propagate and expand numbers of rare or valuable types of individual or species."

The entire study can be perused at the Biology of Reproduction website.

— TJD, GMA News