Pro-megakaryocyte

Scheme electron microscopy. The pro-megakaryocyte (20-80 m) develops from a basophilic megakaryoblast (up to 50 m) that originates from a committed stem cell. The large pro-megakaryocyte starts with the early synthesis of the characteristic granules of platelets. Apart from a bilobed nucleus (1) and few nucleoli, a well developed Golgi area (2), some rough endoplasmic profiles (3) and polysomes are present. This cell contains already electron-dense granules (4)