Presence of a defect in karyokinesis during megakaryocyte endomitosis.

Larissa Lordier, Jiajia Pan, Valeria Naim, Abdelali Jalil, Idinath Badirou, Philippe Rameau, Jerôme Larghero, Najet Debili, Filippo Rosselli, William Vainchenker, Yunhua Chang

Cell cycle (Georgetown, Tex.) 2012 Dec 01

filter terms:

Megakaryocyte is the naturally polyploid cell that gives rise to platelets. Polyploidization occurs by endomitosis, a process corresponding to a late failure of cytokinesis with a backward movement of the daughter cells. Generally, a pure defect in cytokinesis produces a multinucleated cell, but megakaryocytes are characterized by a single polylobulated nucleus with a 2 (N) ploidy. Here, we show the existence of a defect in karyokinesis during the endomitotic process. From late telophase until the reversal of cytokinesis, some dipolar mitosis/endomitosis and most multipolar endomitosis present a thin DNA link between the segregated chromosomes surrounded by an incomplete nuclear membrane formation, which implies that sister chromatid separation is not complete. This observation may explain why polyploid megakaryocytes display a single polylobulated nucleus along with an increase in ploidy.

Citation

Larissa Lordier, Jiajia Pan, Valeria Naim, Abdelali Jalil, Idinath Badirou, Philippe Rameau, Jerôme Larghero, Najet Debili, Filippo Rosselli, William Vainchenker, Yunhua Chang. Presence of a defect in karyokinesis during megakaryocyte endomitosis. Cell cycle (Georgetown, Tex.). 2012 Dec 01;11(23):4385-9