Expression and desaturase activities of recombinant rat FADS1, FADS2, and FADS3 in COS-7 cells. (A) COS-7 cells were transfected with the following plasmids: pCMV empty (control cells), pCMV/FADS1, pCMV/FADS2, and pCMV/FADS3. Immunoblots were assessed on COS-7 cell extracts transiently expressing the recombinant FADS proteins. Recombinant FADS1, FADS2, and FADS3 were detected with polyclonal antibodies targeting specific antigenic peptides of these proteins. Quantitative estimation of protein loading was performed with an anti-actin antibody. Molecular weights are indicated in kDa. (B) GC-MS profiles of FAMEs extracted from COS-7 cells expressing rat FADS1, FADS2, or FADS3 and incubated with α-linolenic acid (18:3 n-3) (C) GC-MS profiles of FAMEs extracted from COS-7 cells expressing rat FADS1, FADS2, or FADS3 and incubated with eicosatrienoic acid (20:3 n-6). Control COS-7 cells and COS-7 cells transiently expressing the recombinant FADS proteins were incubated for 24 h with albumin-bound FA (200 µM). The identity of each important FA is indicated above its respective peak. Representative example of n = 5 distinct experiments.