Fig. 5. Lipid composition and fluidity of liver microsomes from four vertebrate species. (A) Correlation between unsaturated fatty acid content and body temperature. (B) 1,6-diphenyl-1,3,5-hexatriene (DPH) anisotropy at 21°C for each species (mean±s.d., three separate preparations). Note that the relationship between DPH anisotropy values for different species does not change significantly when measurements are done over a temperature range between 2 and 40°C (Logue et al., 2000).