The midbody ring is a circular structure located at the core of the midbody in the cytokinetic bridge. It is a highly dense structure that contains microtubules as well as remnants from the contractile ring. The midbody ring acts as a scaffold for factors involved in the final stages of cytokinesis.
The midbody is a transient structure present during the final stages of cytokinesis. The midbody is found at the center of the cytokinetic bridge. In the Cell Atlas, staining of the region of the cytokinetic bridge with tightly bundled microtubule filaments, as indicated by the microtubule marker, is annotated as midbody. A circular staining in the bulging region that lacks staining by the microtubule maker is annotated as midbody ring.
Read more about the proteome of the midbody ring as a substructure of microtubules.