Sequential phases of neutrophil emperipolesis in MKs from the spleen of GATA-1^low mouse. The different panels present a neutrophil (N) approaching the MK (A); establishing contacts with the MK (B) and fusing its own membrane with that of the MK (arrowheads in the insert in panel B); penetrating the MK through the DMS (C). Finally, panel D shows 2 neutrophils enclosed inside the MK cytoplasm. Note that in this last case, the MK cytoplasm appears highly vacuolated, a sign of cell damage, whereas the cytoplasm of the neutrophil appears degranulated. Nu indicates nuclear area of the MK. Original magnification × 3000 for all panels and × 30 000 for the insert.