Changes in transcripts and lipids of N. oceanica in response to sterol starvation induced by TBF. (A) Transcript profiles of cholesterogenic genes and fatty acid (FA) biosynthetic genes in response to TBF (2.5 mg l-1). Red and green indicate up- and down-regulated genes, respectively. (B) Transcript levels of FAS-g927 gene in N. oceanica induced by TBF (2.5 mg l-1) and nitrogen depletion (N-). (C) Changes in total FA content induced by TBF. (D) Changes of total TAG content induced by TBF. (E) Changes of glycerol lipid classes (other than TAG) induced by TBF. For all experiments, cultures in exponential phase were treated with TBF (2.5 mg l-1) or an equivalent amount of DMSO (control). FA content was analyzed at two, four and six days, and glycerolipid content was analyzed at six days. Asterisks (*) indicate P values < 0.05.