Pigs are offering new possibilities for studying Alzheimer’s disease
Posted 12.09.2008 at 6:37 pm
Making Transgenic Pigs
The researchers achieved two firsts: Their transgenic pigs are the first to carry a human Alzheimer’s gene, and they’re the first pigs produced by a relatively new method called handmade cloning.
A Pig in Hand: A researcher holds one of the pigs that may further our understanding of Alzheimer’s disease. Neils Aage Skovbo/Scanpix
To introduce the disease gene, Jørgensen’s team first removed a fibroblast from an adult female pig. The Alzheimer’s gene was then inserted into the fibroblast. Once the scientists determined that the Alzheimer’s gene was active inside the cell, they allowed it to multiply. They then prepared the pig ova—the cell that will eventually grow into the piglet—to accept the fibroblast’s genetic material. To do this, Gábor Vajta, a cloning expert and an affiliate professor at the University of Copenhagen, used a method he developed in 2001. The key: using enzymes to dissolve the zona pellucida, or outer membrane, of the egg. This allowed the scientists to easily manipulate the egg cell’s components by hand, rather than using micromanipulators, tiny instruments used in traditional cloning [for more on this process see “An Easier Way to Clone” on the last page].
Vajta then fused the fibroblast carrying the Alzheimer’s gene with the egg cell, which was electrically and chemically stimulated to ultimately become a blastocyst, an embryonic phase. The team produced 40 to 50 identical blastocysts using Alzheimer’s fibroblasts that had multiplied from the original. Veterinarians implanted these blastocysts into a sow.