FIGURE 1.

S1P lyase deficiency affects primarily mass of sphingoid bases and their phosphates. Neuronal cultures were prepared from wild type (+/+) and S1P lyase-deficient (−/−) mouse cerebella. At day 5 in culture, cells were harvested, and lipids were extracted and evaluated by ESI-tandem mass spectrometry as described under “Experimental Procedures.” Data are averages of triplicate determinations. Numbers indicate carbon chain length followed by the number of double bounds in the fatty acid moiety. Sa, sphinganine; Sa1P, sphinganine 1-phosphate; Sph, sphingosine; SM, sphingomyelin; DHGlcCer, dihydroglucosylceramide; DHSM, dihydrosphingomyelin; DHCer, dihydroceramide; Cer, ceramide; DHsphingolipids, dihydrosphingolipids.