Fig. 3. Exocrine pancreas and secretory granule morphology in Sc5d^-/- mice (lathosterolosis model) at E18.5. (A,B) Sc5d^-/- animals consistently show a marked reduction in the number of dense core granules. In addition, many aberrant morphological profiles were evident: (C) large phagocytic structures with features of late endosomes or lysosomes engulfing cellular debris and granular material (arrows); (D) complete absence of dense core vesicles, and an abundance of ribosomal structures and rough ER; (E) enlarged ER (arrows). (F) A few areas have dense core vesicles similar to Sc5d^+/+ (WT), interspersed with profiles of enlarged ER. (G) Quantitative analysis of granule number in lathosterolosis mouse model. Sc5d^+/+ and Sc5d^-/- groups contain four animals each. Ten different areas of each pancreas were imaged at low EM magnification (3150x) and counted. Bars, 2 µm (A-C,F); 1 µm (D-E).