PRC1 localized normally to the central spindle during endomitosis. MKs were stained for tubulin (α and β, green), PRC1 (red), and TOTO (blue). The anti-α and anti-β tubulin antibodies mark the central spindle. (A) During anaphase, microtubules congregated midway between the 2 poles of the central spindle, while PRC1 accumulated in the midzone and colocalized with the central spindle. (B) During telophase, the central spindle was highly concentrated, forming 1 intercellular bridge. PRC1 was present in the center of the central spindle.