Absence of alloimmune memory in the freshwater sponge [formula omitted

Abstract

Second-set allograft experiments were performed on the freshwater sponge, Ephydatia fluviatilis, in order to determine the eventual existence of a specific memory component. Graft rejection resides in an early collagen layer deposition at the interface of the foreign individuals. Based on the challenge time of collagen layering, our results demonstrate that for Ephydatia fluviatilis, a second-set graft rejection gives neither accelerated nor intensified reactions. Consequently, a specific memory component fails in Ephydatia.