Fatty acid analysis of Saccharomyces cerevisiae expressing wt and mutant BoFAD3-2 by GC-MS. FAMEs of total lipids from three independent colonies grown under inducing conditions in the presence (A) or absence (B) of 150 μM exogenously supplied linoleic acid (exo C18:2). Chromatograms are representative of yeast bearing either wt BoFAD3-2 (wt), mutant BoFAD3-2 (mut) or empty vector (EV) and display major common peaks (C16:0, C16:1, C18:0 and C18:1). The standard, C17:0 (STD), is also depicted in each case. α-linolenic acid (C18:3) generated by the wt and mutant BoFAD3-2 enzymes in C18:2 supplemented cultures is designated by an asterisk. While all cultures supplied with exogenous C18:2 display a large corresponding peak (exo C18:2), only relatively small peaks of C18:2 were observed in non-fed yeast, which are indicated by an arrow.