Fig. 1. Expression and distribution of SR-BI protein along the duodenal crypt-villus axis. Representative indirect immunofluorescence micrographs of cryosections are shown for 14 weeks (A,B) and 20 weeks (C) of gestation, as well as for the adult period (D). Immunofluorescence was also visualized in the microvascular endothelial cells of the lamina propria (E) and muscle cells (F). In all cases, no fluorescent staining was observed when the primary SR-BI antibody was replaced with the appropriate nonimmune serial (data not shown).