Hot topic: using a stearoyl-CoA desaturase transgene to alter milk fatty acid composition.
Stearoyl-CoA desaturase enzyme converts specific medium- and long-chain saturated fatty acids to their monounsaturated form. Transgenic goats expressing a bovine beta-lactoglobulin promoter-rat stearoyl-CoA desaturase cDNA construct in mammary gland epithelial cells were produced by pronuclear microinjection. The fatty acid composition of milk from 4 female transgenic founders was analyzed on d 7, 14, and 30 of their first lactation. In 2 animals, the expression of the transgene changed the overall fatty acid composition of the resulting milk fat to a less saturated and more monounsaturated fatty acid profile at d 7 of lactation; however, this effect diminished by d 30. In addition, one animal had an increased proportion of the rumen-derived monounsaturated fatty acid C18:1 trans11 converted by stearoyl-CoA desaturase to the conjugated linoleic acid isomer C18:2 cis9 trans11. Milk that has higher proportions of monounsaturated fatty acids and conjugated linoleic acid may have benefits for human cardiovascular health.
Reh
W A
WA
Department of Animal Science, University of California, Davis 95616, USA.
Maga
E A
EA
Collette
N M B
NM
Moyer
A
A
Conrad-Brink
J S
JS
Taylor
S J
SJ
DePeters
E J
EJ
Oppenheim
S
S
Rowe
J D
JD
BonDurant
R H
RH
Anderson
G B
GB
Murray
J D
JD
D000818:Animals; D030801:Animals, Genetically Modified; D002417:Cattle; D018076:DNA, Complementary / Q000235:genetics; D004847:Epithelial Cells / Q000201:enzymology; D005227:Fatty Acids / Q000032:analysis*; D005229:Fatty Acids, Monounsaturated / Q000032:analysis; D005260:Female; D015870:Gene Expression; D006041:Goats / Q000235:genetics*; D007774:Lactation; D007782:Lactoglobulins / Q000235:genetics; D044243:Linoleic Acids, Conjugated / Q000032:analysis; D008321:Mammary Glands, Animal / Q000201:enzymology; D008892:Milk / Q000737:chemistry*; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats; D013230:Stearoyl-CoA Desaturase / Q000235:genetics* / Q000378:metabolism
D018076:DNA, Complementary; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D007782:Lactoglobulins; D044243:Linoleic Acids, Conjugated; D013230:Stearoyl-CoA Desaturase