Impaired Spleen Formation Perturbs Morphogenesis of the Gastric Lobe of the Pancreas
Figure 1
The gastric lobe constitutes a significant portion of the mouse pancreas and is formed by perpendicular growth from the stalk of the dorsal pancreas into a lateral mesenchymal domain positioned in close proximity to the pyloric sphincter and pyloric antrum.
(A) Photomicrograph of a gut segment including the stomach, duodenum, spleen and pancreas from a C57Bl/6 mouse at 8 weeks. (B) Graph depicting the 10log values of the epithelial volume of the DP (yellow diamond), VP (green square), GL (yellow triangle) and the entire pancreas (black cross) between e10.5 and 8 weeks. (C) Relative lobular volumes between e10.5 and 8 weeks. From e15.5 onwards, the gastric lobe constitutes more than 10% of the pancreatic epithelium. DP: red; VP: green; GL: yellow. Data in (B, C) is derived from analyses of C57Bl/6 mice. Values in (C) are given ± SEM. (D through Q) OPT generated iso-surface reconstructions of gut segments including the stomach, duodenum, spleen and pancreas between e10.5 to e17.5 based on the signal from E-cadherin antibodies (epithelium, D to J) and the signal from tissue autofluorescence (mesenchyme, K to Q). The condensation and migration of primordial spleen cells in an anterior direction results in the formation of a lateral mesenchymal domain which provides the template for growth from the stalk of the dorsal pancreatic epithelium. (D to J) The dorsal, ventral and gastric epithelium have been pseudocolored red, green and yellow respectively. (L to N) The dorsal mesenchyme and the spleen primordium have been pseudocolored blue and pink respectively. The specimens in (D–Q) are not depicted to scale. Scale bar in A is 3 mm.