Functional expression of a Δ12 fatty acid desaturase gene from spinach in transgenic pigs

Abstract

Linoleic acid (18:2n-6) and ␣-linolenic acid (18:3n-3) are polyunsaturated fatty acids that are essential for mammalian nutrition, because mammals lack the desaturases required for synthesis of ⌬12 (n-6) and n-3 fatty acids. Many plants can synthesize these fatty acids and, therefore, to examine the effects of a plant desaturase in mammals, we generated transgenic pigs that carried the fatty acid desaturation 2 gene for a ⌬12 fatty acid desaturase from spinach. Levels of linoleic acid (18:2n-6) in adipocytes that had differentiated in vitro from cells derived from the transgenic pigs were Ϸ10 times higher than those from wild-type pigs. In addition, the white adipose tissue of transgenic pigs contained Ϸ20% more linoleic acid (18:2n-6) than that of wild-type pigs. These results demonstrate the functional expression of a plant gene for a fatty acid desaturase in mammals, opening up the possibility of modifying the fatty acid composition of products from domestic animals by transgenic technology, using plant genes for fatty acid desaturases.

The use of genetic engineering techniques to improve the lipid composition in meat, milk and fish products: a review

“…The transgenesis significantly affected the fatty-acid composition of lipids in tissues of modified pigs, that is the white adipose tissue of transgenic pigs contained 20% more LA in comparison with wild pigs. As stressed by the authors, the results of their study demonstrated the functional expression of a plant gene for a fatty-acid desaturase in mammals, opening prospects of modifying the lipid composition of animal-origin products using transgenic technology (Saeki et al, 2004). Since the authors produced four transgenic pigs of the third generation farrowed by a transgenic female, and all of them grew to a fertile age, their results indicated that it is a possibility to transferring desaturase transgene to subsequent generations.…”

“…One of the first of this kind of experiment is a spectacular example of transgenesis in which a plant transgene was introduced into the genome of a mammal. Thus, Saeki et al (2004) generated, through microinjection of foreign (plant) DNA to the pronuclei of zygotes, transgenic pigs that expressed the Δ12 fatty-acid desaturase gene (fad-2) from spinach (Spinacia oleracea). This enzyme is necessary for the synthesis of LA (C18:2 n-6) and ALA (C18:3 n-3), which are necessary for normal growth and development.…”

Genetic Modification of Domestic Animals for Agriculture and Biomedical Applications

“…The application of transgenic technology offers a powerful tool to rapidly improve agriculture production by developing domestic animals that express desired traits via genome manipulation strategies. Previous studies have demonstrated the practical application of transgenesis to improve numerous agricultural traits of domestic animals, including increased growth rate (Pursel et al, 1999), increased meat quality (Saeki et al, 2004), enhanced disease resistance (Lo et al, 1991;Clements et al, 1994), and better milk production and composition (Wheeler et al, 2001;Reh et al, 2004). Nevertheless, utilization of the cell-based method of transgenesis via SCNT has also been successfully used to alter characteristics of pork quality (Lai et al, 2006), enhance disease resistance (Denning et al, 2001a;Wall et al, 2005;Richt et al, 2007) and improve milk composition (Brophy et al, 2003).…”

Relations between animal transgenesis and reproduction

“…This is the case for pigs expressing a desaturate gene from spinach which enhances the proportion of now saturated lipids [41].…”