Figure 2. apoB mutants exhibit defective liver development and steatosis.

(A) Confocal images at 4 dpf of apoBa^–/– and apoBa^–/– apoBb.1^MO embryos in Tg(-2.8fabp10a:EGFP)^as3 background, showing smaller liver and decreased expression of fabp10a EGFP in apoBa^–/– apoBb.1^MO embryos (n_WT = 8/8, n_{apob–/– apoBa–/– apoBb.1MO} = 7/7). (B) No apoptotic cells are detected in the liver of apoBa^–/– or apoBa^–/– apoBb.1^MO embryos, following TUNEL staining (n_WT = 6/6, n_{apoBa–/– apoBb.1MO} = 5/5). (C) WISH showing expression of fabp10a at 4 dpf, depicting decreased liver size in apoBa^–/– apoBb.1^MO embryos (n_WT = 7, n_{apoBa–/– apoBb.1MO} = 13). (D and E) WISH with riboprobes against prox1a at 2 dpf (D) (n_WT = 4/4, n_{apoBa–/– apoBb.1MO} = 7/9) and tfa at 4 dpf (E) (n_WT = 7/7, n_{apoBa–/– apoBb.1MO} = 5/6) shows bilateral liver buds in apoBa^–/– apoBb.1^MO embryos as opposed to apoBa^–/– mutants, which display a single liver bud located to the left of the midline. (F) Expression of forkhead box a2 (foxa2) at 2 dpf remains unchanged in apoBa^–/– apoBb.1^MO embryos as compared with apoBa^–/– siblings. (G) Confocal images of 5 dpf Tg(12xNRE:Egfp) embryos with outlined livers, showing decreased Notch signal in the bile ducts of apoBa^–/– apoBb.1^MO embryos (n_WT = 4, n_apoBa–/– = 8, n_{apoBb1–/–} = 6, n_{apoBa–/– apoBb.1MO} = 20). (H) Confocal images of Nile red staining at 4 dpf depicting neutral lipid accumulation in apoBb.1^MO and apoBa^–/– apoBb.1^MO embryos. Red staining labels polar lipid; green fluorescence highlights neutral lipids (n_WT = 5, n_apoBa–/– = 8, _{napoBb.1–/–} = 5, n_{apoBa–/– apoBb.1MO} = 9). Scale bar: (A, B, G, and H) 50 μm, (C–F) 100 μm.