Osteoclasts and monocytes have similar cytoskeletal structures and adhesion property in vitro.

The distribution of some cytoskeletal structures (microtubules, microfilaments, intermediate filaments) has been studied by indirect immunofluorescence microscopy and affinity purified antibodies in osteoclasts isolated from medullary bone of laying hens and in hen blood monocytes cultured in vitro. Both cell types show similar patterns of distribution of cytoskeletal structures and this further supports the concept that these cells are closely related. Osteoclasts and monocytes are also similar in their adhesion patterns, because they adhere to fibronectin-free areas and show closely comparable cell-to-substrate interactions when observed with interference reflection microscopy.