Figure 1.
Mouse gallbladder and pancreas development. (A) Mouse pancreatic gut schematic showing developing stomach (St), liver (L), dorsal pancreatic bud (DP), and the ventral pancreatic bud (VP) that gives rise to the gallbladder (Gb) and ventral pancreas. TaqMan-based real-time qPCR for rodent insulin genes (Ins1, Ins2), the master regulatory transcription factor (Pdx1) (B) as well as other genes (C) in developing mouse pancreas and gallbladder tissues harvested on E15.5, E16.5, and E18.5. Data in B and C represent means ± SD from 3 different litters of Friend Virus B NIH Jackson (FVB/NJ) mice, each with at least 6–7 embryos/litter. Transcript abundance was analyzed using 2-way analysis of variance with the Sidak adjustment for multiple comparisons. Each point in the scatter bar graph presents data from a single litter. (D) Insulin content in developing mouse pancreas and gallbladder tissues harvested at E16.5, E18.5, and neonatal day 1 pups. Data were obtained from pooled tissues from 3 different litters of FVB/NJ mice, each with at least 6–7 embryos/pups and presented after normalizing to total protein. Aligned dot plots present means ± SEM. Significance was calculated using 2-way analysis of variance with the Fisher's Least Significant Difference (LSD) test. (E and F) Pdx1GFP/w reporter mouse embryos were obtained from timed pregnancies (E10.5, E13.5, and E15.5) and GFP fluorescence (arrowheads) was used to identify pancreatic buds. Representative flow cytometry plots of pancreas and gallbladder tissues from Pdx1GFP/w (GFP+) and Pdx1w/w (wild-type) mice are presented with proportions of GFP+ cells as indicated. Acquisition and gating parameters were identical across WT and GFP+ tissues. Experiments were repeated at least 3 times with tissues pooled from 6 to 7 embryos. (G) Volcano plot for bulk RNA-seq data from the adult mouse gallbladder (n = 6) and pancreas (n = 6). Normalized read count difference between pancreas and gallbladder is plotted on the X-axis and statistical significance (−log10P value) is presented on the Y-axis. The dashed horizontal line represents P = .05, and the dashed vertical lines represent a 2-fold normalized DEseq value difference. Significantly altered (P ≤ .05 and ≥2-fold difference) transcripts are presented in red. Selected important pancreatic genes on the volcano plot are labeled and highlighted in purple. Throughout the figure, bars/dots for the pancreas are in red and for the gallbladder are in green. ∗P < .05, ∗∗P < .01