Transgenic Dogs Research Articles

Generation of red fluorescent protein transgenic dogs

Dogs (Canis familiaris) share many common genetic diseases with humans and development of disease models using a transgenic approach has long been awaited. However, due to the technical difficulty in obtaining fertilizable eggs and the unavailability of embryonic stem cells, no transgenic dog has been generated. Canine fetal fibroblasts were stably transfected with a red fluorescent protein (RFP) gene-expressing construct using retrovirus gene delivery method. Somatic cell nuclear transfer was then employed to replace the nucleus of an oocyte with the nucleus of the RFP-fibroblasts. Using this approach, we produced the first generation of transgenic dogs with four female and two male expressing RFP.

Dogs cloned from fetal fibroblasts by nuclear transfer

Fetal fibroblasts have been considered as the prime candidate donor cells for the canine reproductive cloning by somatic cell nuclear transfer (SCNT) in regard to the future production of transgenic dogs, mainly due to their higher developmental competence and handling advantage in gene targeting. In this study, the cloning efficiency with canine fetal fibroblasts as donor cells was determined. A total of 50 presumptive cloned embryos were reconstructed, activated and transferred into the oviducts of naturally synchronous recipient bitches. While the fusion rate (76.9%) was similar to those of our earlier studies with adult fibroblasts as donor cells (73.9–77.1%), a high cloning efficiency (4.0%; 2 births/50 embryos transferred) was found compared to the previous success rate with adult fibroblasts (0.2–1.8%). The cloned beagles were healthy and genotypically identical to the donor fibroblast cells. This study shows that a fetal fibroblast cell would be an excellent donor for future production of transgenic dogs via gene targeting in this cell followed cloning using SCNT technology.

Fluorescent pet rabbit fuels GM debate

The arguments about the applications of GM technology rage on, and now US-based artist Eduardo Kac has caused a further media stir through his recent explorations in ‘transgenic art’. His first such work, displayed in 1999, featured Escherichia coli transformed with genes encoding jellyfish green-fluorescent protein (GFP) derivatives. He also proposed the making of a transgenic dog, to be christened GFP-K9. An editorial in Nature Biotechnology (October 1999) suggested that this work could help promote the sensible discussion of GM issues, despite the obvious potential for trivialization. Now, instead of GFP-K9, a rabbit expressing GFP has been successfully made in collaboration with scientists in France, which Kac wants to take home as a family pet. The future for ‘GFP Bunny’ is unclear, owing to the legal issues regarding the release of such an organism. This has provoked another editorial, this time in the Boston Sunday Globe (24 September 2000), which seriously questions the wisdom of making transgenic animals for nonscientific endeavors. Whatever the case, Kac has certainly added some new spice to the debate about the role of genetically modified organisms in society. Check out www.ekac.org for more details.