An automatic image analysis of megakaryocytes in fetal liver and adult bone marrow.

The size distribution of megakaryocytes in fetal liver and adult bone marrow was measured with an image processing system AMPA. In the liver, the size of the mature megakaryocytes increased gradually with fetal age. On the 18th fetal day the size of cells became nearly the same as that in the liver of newborn rats. However, the megakaryocytes in the bone marrow had a significantly wider size distribution than those in the liver. These results point to some features of the differences of megakaryocytopoiesis between fetal liver and bone marrows after birth.