In the pancreas of mammals, digestive enzymes are transported from their production site in acini (clusters of cells that secrete the enzymes) to the intestine via a network of ducts. During organ development in fetuses, the ducts initially form by the coordinated polarization of cells to form small holes, which will connect and fuse, to constitute a meshwork. This hyperconnected network further develops into a treelike structure by the time of birth. This study by Dahl-Jensen et al. uses methods originally developed to analyze road, rail, web, or river networks to quantify the network properties at different developmental stages. The authors find that the pancreatic network properties are similar between individuals at specific time points but eventually change to achieve the most economical and optimized structure to deliver pancreatic juice into the duodenum. The image shows a confocal immunofluorescent microscopy image of the pancreas from a mouse embryo at 18.5 days' gestation. Pancreatic ducts (as well as the surrounding duodenum) are shown in green (stained for β-catenin) and the islets of Langerhans appear in red (stained for insulin).

Image Credit: Dror Sever