Figure 13.

Acyl chain flux into membrane lipids during N-resupply in timecourse B. Triacylglycerol TAG and de novo FA synthesis contribution to membrane lipids during early and late N-resupply, respectively. Colored arrows represent acyl chain remodeling from TAG into membrane lipids at 12 h of N-resupply after labeled acetate was supplied during N-deprivation (Figure 1B). Arrow weights are based on the quantity of each FA and divided into low, intermediate, and high levels of labeling based on the isotopic label distribution of each FA in membrane lipids. De novo FA synthesis contributes significantly to membrane lipid synthesis in later stages of N-resupply when TAG has been depleted. Black arrows indicate routes of fatty acyl chain movement without indicating relative quantities and sequential black arrows indicate multi-step pathways.