Jan. 15, 2003 -- A new technique may make it easier to create genetically modified pigs to serve as organ donors for humans. Researchers say they've developed a way to transfer human genes into pig embryos using pig sperm rather than more expensive methods.
In the past, researchers say genetically modified animals could only be produced by injecting genetic material into the embryos, which is the same process used in cloning. Although this method works well in mice, it isn't very efficient in larger animals and livestock.
But a new study shows transgenic animals -- animals that have part of another species' DNA transferred into its own -- may also be produced using a technique that is more efficient and cost-effective than the injection method. By using pig sperm to transfer the gene via fertilization rather than injection into the embryo, researchers say they were able to successfully produce piglets with a human gene that makes their organs less likely to be rejected by human immune systems.
The procedure is described in the March issue of Molecular Reproduction and Development.
Study author Marialuisa Lavitrano, of the Universita di Milano-Bococca, and colleagues generated genetically altered sperm samples that were used to fertilize 15 female pigs. The DNA of more than half of 93 piglets produced through fertilization contained the transferred human DNA material. Of those piglets, human genes were found in all of the tissue that was tested.
Researchers say the advantage of this technique over the injection method is that it produces many more transgenic pigs at a much lower cost. In addition, this technology may also be developed and applied to other biomedical fields.
They say they hope that this method can speed the introduction of other transgenic livestock.
SOURCE: Molecular Reproduction and Development, March 2003.