Distinct lipid species are asymmetrically distributed in the testis. Lipid imaging by MALDI on control or Acsl6−/− testes reveal distinct lipid species distribution patterns for PC 36p:3 m/z = 806.546 [M+K]+; PC 36:1 m/z = 826.5723 [M+K]+; and PC 42p:6 m/z = 884.593 [M+K]+ (A); PC 32:0 m/z = 772.5253, [M+K]+; PC40:5 m/z = 874.5723, [M+K]+ (B); and SM d34:1 m/z = 741.5307, [M+K]+; SM d36:1 m/z = 769.562, [M+K]+ (C) in control and Acsl6−/− testes. Scale bars, 1 mm.