A comparison of the appearance of the bile (a) and the biliary lipid concentrations and composition (b) in the ABCG5/ABCG8 transgenic mice and littermate controls. The gallbladder bile was collected from 12-week-old wild-type (n = 4 in each group) and transgenic (n = 5 in each group) mice. The mice were fed ad libitum a chow diet and sacrificed nonfasted in the mid–light cycle. The biliary cholesterol, bile acids, and phospholipids were measured as described in Methods. This experiment was repeated in another line of transgenic mice (6–1), and the results were similar. * P < 0.05, **P < 0.01.