Which RBC precursor is the last to retain the nucleus before maturation into an erythrocyte?

The metarubricyte, also known as the late erythroblast, is the last red blood cell precursor to retain its nucleus before maturing into an erythrocyte. At this stage, the cell is involved in the synthesis of hemoglobin and is preparing for the final stages of maturation.

When the metarubricyte develops, it undergoes a series of changes that lead to the expulsion of its nucleus, resulting in the formation of the reticulocyte. This process is crucial for the transition from a nucleated cell to a mature, non-nucleated erythrocyte, which is essential for effective oxygen transport in the bloodstream.

Understanding the maturation process and the specific stages of erythropoiesis helps in recognizing the significance of each precursor stage and its role in producing functioning red blood cells.