Stearoyl-CoA desaturase (SCD) is a lipogenic enzyme that catalyzes the synthesis of monounsaturated fatty acids. High SCD activity appears in a wide range of disorders including diabetes, atherosclerosis and obesity but its physiological role has been unclear. In August 12 advanced online, Proceedings of the National Academy of Sciences, James Ntambi and colleagues from University of Wisconsin-Madison, Wisconsin, US, show that loss of SCD function in mice results in global changes in gene expression and altered metabolic activity that accounts for the loss of body fat (Proc Natl Acad Sci USA 2002, 10.1073/pnas.132384699).

Ntambi et al. studied mice with a targeted disruption of the SCD1 isoform and observed that these animals have reduced body adiposity, increased insulin sensitivity and are resistant to diet-induced weight gain. These effects stemmed from increased energy expenditure and oxygen consumption. In addition, they show that in the SCD1^-/- mice, the expression of...