Nuclear Transfer

Nuclear transfer is a method for producing animals whose nuclear genetic material is derived solely from a donor cell from an individual animal ("clones"). In this process, the nucleus containing the chromosomal DNA is removed from an animal egg cell and subsequently replaced with a nucleus from a donor somatic (non-reproductive) cell. Fusion between the enucleated egg cell and the donor somatic nucleus results in a new cell that contains a complete set of chromosomes derived entirely from the donor nucleus. Mitochondrial DNA, providing some of the genes for energy production, resides outside the nucleus and is provided by the egg. A brief culture period enables the donor nucleus within the reconstituted egg cell to initiate embryonic development. The egg cell cytoplasm, the fluid that fills cells, is able to reprogram the donor nucleus to express all the genes eventually required for the full embryonic development of the animal. The early stage embryo is implanted into the uterus of a female animal, where it can fully develop and result in the live birth of a cloned offspring animal. The offspring is essentially a genetic clone of (genetically identical to) the animal from which the donor nucleus was obtained.

In early 1997, scientists at the Roslin Institute were the first to demonstrate, with the birth of Dolly the sheep, that the nucleus of an adult cell can be transferred to an enucleated egg to create cloned offspring. Dolly was a significant achievement because it established that it is possible to reprogram an adult cell. Since then, the technique has been used to clone mice, rats, goats, cattle, rabbits, cats, pigs, dogs and horses. Nuclear transfer technology has many potential applications in biotechnology.

In agriculture, there is current interest in cloning selected livestock that are rare or that have desired genetic traits, such as disease resistance, improved meat quality or yield, or increased milk production. These cloned livestock would be used in breeding programs to incorporate their positive genetic traits into herds more quickly than is possible through conventional breeding and artificial insemination. The aim is to upgrade the food products that are available to consumers. The Food and Drug Administration conducted a risk assessment and reported on January 15, 2008 "After years of detailed study and analysis, the Food and Drug Administration has concluded that meat and milk from clones of cattle, swine and goats, and the offspring of clones from any species traditionally consumed as food, are as safe to eat as food from conventionally bred animals." The full report is available at http://www.fda.gov/cvm/CloneRiskAssessment_Final.htm

For human medicine, animal cloning has a range of applications that include generating animal models of human disease for research, developing animals that secrete therapeutic proteins in their milk, or produce humanized antibodies, or have modified organs for xenotransplantation to patients.

In 1999, we acquired Roslin Bio-Med Ltd., a commercial subsidiary of the Roslin Institute, and an exclusive license to the patents for nuclear transfer technology for multiple applications in animal and human biology. In 2005, we formed a joint venture with Exeter Life Sciences, Inc., called Start Licensing, Inc., a new company to manage and license a broad portfolio of intellectual property rights related to animal reproductive technologies, including the full range of applications for nuclear transfer. In 2008, we merged Start Licensing, Inc., with ViaGen, Inc., a leading animal genomics and livestock cloning firm, to create a one-stop licensing and operating company.