haemoglobin content, haematocrit levels and improved survival compared to
untreated controls.
DNA vaccination has also been used in dogs to control seasonal allergy to
Japanese cedar pollen (Masuda 2005 ) and immunostimulatory liposome–plasmid
complexes have been used to treat refractory atopic dermatitis in dogs (Mueller
et al. 2005 ).
Delivery of porcine GHRH plasmid by electroporation has been shown to
decrease morbidity and mortality in treated sows and their offspring over three
consecutive pregnancies (Person et al. 2008 ). This technology was approved for use
in food animals in Australia in January 2008 under the name of LifeTide SW 5
marketed by VGX Animal Health Inc.
7 Summary
Genetic modification of laboratory and farm animals has enabled a greater under-
standing of gene function, development of animal models of human disease, insight
into new targets for pharmacological development, the production of biopharma-
ceuticals, disease resistant farm animals, a possible source of transplants and
genetic therapies for man and companion animals. These developments can only
increase with a detailed knowledge of the genome for each of the domestic species.
It is important to understand the technology and thus limitations to these genetic
modifications. The development of IPS cells presents an opportunity to improve the
efficiency of genetic modification and thus make transgenic farm animals a more
attractive option for the future provided the marketing of meat and milk is accepted
by the regulatory authorities and the public. The most promising area for future
development appears to be the use of gene therapies in companion animals as this
has the potential to produce beneficial results for both animals and man.
References
Aguirre GD, Baldwin V, Pearce-Kelling S, Narfstro ̈m K, Ray K, Acland GM (1998) Congenital
stationary night blindness in the dog: common mutation in the RPE65 gene indicates founder
effect. Mol Vis 30:23
Bergman PJ, McKnight J, Novosad A, Charney S, Farrelly J, Craft D, Wulderk M, Jeffers Y,
Sadelain M, Hohenhaus AE, Segal N, Gregor P, Engelhorn M, Riviere I, Houghton AN,
Wolchok JD (2003) Long-term survival of dogs with advanced malignant melanoma
after DNA vaccination with xenogeneic human tyrosinase: A phase I trial. Clin Cancer Res
9:1284–1290
Bodles-Brakhop AM, Brown PA, Pope MA, Draghia-Akli R (2008) Double-blinded, placebo-
controlled plasmid GHRH trial for cancer-associated anemia in dogs. Mol Ther 16:862–870
Brinster RL, Chen HY, Trumbauer ME, Yagle MK, Palmiter RD (1985) Factors affecting
the efficiency of introducing foreign DNA into mice by microinjecting eggs. Proc Natl Acad
Sci USA 82:4438–4442
222 D.J. Wells