Bone marrow

  • In birds, a lymphoid organ called the "Bursa of fabricius", which is a gut-associatedbone marrow lymphoid tissue, is the primary site of B-cell maturation.
  • In mammals, such as primates and rodents, there is no Bursa, but Bone marrow serve as the "Bursal equivalent", where B-cell maturation occurs.
  • In rabbits, uses gut-associated tissues such as the Appendix as primary lymphoid tissue for important steps in the proliferation and diversification of B-cells.

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