Fig. 2. Sphingolipid biosynthesis is reduced by myriocin treatment or TbSPT2 RNAi. The T. brucei 29-13 cell line was grown in the absence or presence of myriocin (1.5 µM) for 1 day; TbSPT2 RNAi cells were grown for 3 days in the presence or absence of Tet and pulse-labeled with [³H]serine for 40 minutes. Lipids were extracted using the Blight-Dyer method and resolved by TLC and visualized by autoradiography. Each lane contains material from 5x10⁸ cells. Positions of phosphatidylethanolamine (PE) and phosphatidylserine (PS) and ceramide standards are indicated.