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Why can white blood cells make proteins while red blood cells cannot?

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Illustration of a blood vessel with a cutaway view showing red blood cells, white blood cells, platelets, and plasma, each labeled to highlight the main components of blood. — white blood cell Blood is made up of multiple components, including red blood cells, white blood cells, platelets, and water-rich plasma.

White blood cells are capable of protein synthesis because they possess a nucleus, which serves as the control center for gene expression. Within the nucleus, the cell’s DNA is transcribed into messenger RNA (mRNA), which is then transported to the cytoplasm to be translated into proteins by ribosomes.123

In contrast, mature mammalian red blood cells cannot synthesize proteins because they lack a nucleus and other essential organelles. During their development in the bone marrow, red blood cells lose their nuclei and mitochondria to maximize internal space for hemoglobin, the protein responsible for oxygen transport. Because they lack the genetic machinery and the organelles required for protein production, mature red blood cells are unable to synthesize new proteins.41