Mononuclear phagocytes are produced by -
The monocyte is formed in the bone marrow and transpoed by the blood ; it migrates into the tissues, where it transforms into a histiocyte or a macrophage. Reff: Ananthanarayanan & Panikers textbook of microbiology 9th edition pg:137
Thymus
Spleen
Bone marrow
Liver
Immunology