The development of the immune tissues in marsupial pouch young

Current knowledge of the development of the marsupial immune system, particularly in the context of lymphoid tissue development and the appearance of lymphocytes, has been examined and limitations identified. While primary lymphoid tissues like the thymus have been extensively studied, secondary lymphoid tissues such as the spleen and lymph nodes have been examined to a lesser extent, partly due to the difficulty of macroscopically identifying these structures, particularly in very small neonates. In addition, little research has been conducted on the mucosal‐associated lymphoid tissues; tissues that directly trap antigens and play an important role in the maturity of adaptive immune responses. Research on the development of the marsupial immune tissues to date serves as a solid foundation for further research, particularly on the mechanisms behind the development of the immune system of marsupials. With the recent sequencing and annotation of whole marsupial genomes, the current wealth of sequence data will be essential in the development of marsupial specific reagents, including antibodies, that are required to widen our specific knowledge of the complex marsupial immune system and its development. J. Morphol. 275:822–839, 2014. © 2014 Wiley Periodicals, Inc.