Gut-Associated lymphoid tissue (GALT) in the amphibian urodele Pleurodeles waltl

Even though salamanders are supposed to lack intestinal lymphoid tissue, Pleurodeles waltl shows lymphoid aggregates throughout the gut, especially in the small intestine, as cell infiltrates in the lamina propia. They have a phylogenetic significance in relation to the existence of an intestinal immunologic barrier in vertebrates.