The evolutionary history of lymphoid organs.

摘要: Lymphoid organs are important regulators of lymphocyte development and immune responses. During vertebrate evolution, primary lymphoid appeared earlier than secondary organs. Among the sites lymphopoiesis during evolution ontogeny, those for B cell differentiation have differed considerably, although they often had myelolymphatic characteristics. In contrast, only a single site T has occurred, exclusively thymus. Based on observations known features variable-diversity-joining gene recombination, we propose model successive specification different lineages evolution. According to our model, cells were first lymphocytes acquire variable-diversity-joining-type receptors, thymus was organ evolve in vertebrates deal with potentially autoreactive, somatically diversified receptors.