Cell division marker
This application relates to a newly identified animal cell structure, the midbody scar. This structure is a remnant of the midbody that is retained by one daughter cell following cytokinesis and persists through multiple subsequent cell cycles. The midbody scar can be useful as a marker of dividing cells or of a cell's replicative age.
1. A method of detecting the presence of a midbody scar in a mammalian cell, the method comprising:
contacting a mammalian cell suspected to have a midbody scar with an antibody or antigen-binding portion thereof that binds specifically to a polypeptide component of a midbody scar selected from the group consisting of mitotic kinesin-like protein 1 (MKLP1), Epsilon tubulin (ε-tubulin), Centrosomal Protein 55 kDa (Cep55), and Aurora B kinase;
detecting binding of the antibody to its antigen; and
identifying a midbody scar in the mammalian cell if binding of the antibody to its antigen is detected in a ring structure not at a midbody or centrosome, thereby detecting a midbody scar.
2. The method of claim 1 , comprising:
contacting the mammalian cell with two or more antibodies or antigen-binding portions thereof that each bind specifically to a polypeptide component of a midbody scar, and
detecting binding of the two or more antibodies,
wherein colocalized binding of the two or more of antibodies indicates the presence of a midbody scar.
3. The method of claim 2 , wherein the polypeptide is selected from the group consisting of mitotic kinesin-like protein 1 (MKLP1); Epsilon tubulin (ε-tubulin); Centrosomal Protein 55 kDa (Cep55); and Aurora B kinase.
4. The method of claim 1 , wherein the cell is in interphase.
5. The method of claim 1 , wherein the mammalian cell is a fixed cell.
6. The method of claim 5 , wherein the fixed cell is in a pathology specimen.
7. The method of claim 1 , wherein the cell is in tissue.
8. The method of claim 1 , wherein the antibody or antigen-binding portion thereof is bound or linked to a detectable moiety.
9. The method of claim 8 , wherein detecting binding of the antibody to its antigen comprises detecting the detectable moiety.
10. The method of claim 1 , wherein the ring structure is about 2 μm in diameter.
11. The method of claim 1 , wherein the ring structure is localized adjacent to the plasma membrane.
12. The method of claim 1 , wherein the ring structure is determined not to comprise detectable gamma tubulin.