Final Answer:
During human development, β-globin gene expression undergoes a transition from ε-globin in early embryonic stages to γ-globin in fetal development, followed by a shift to adult β-globin after birth.
Step-by-step explanation:
The expression of β-globin genes undergoes dynamic changes during human development. Early in embryonic development, the ε-globin gene is expressed, followed by a switch to the γ-globin genes during fetal development.
As the fetus transitions to the neonatal stage, there is a gradual decrease in γ-globin expression and a concurrent increase in the expression of the adult hemoglobin β-globin gene. This switch from fetal to adult hemoglobin expression is a finely regulated process orchestrated by developmental stage-specific transcription factors.
The coordinated temporal expression of these globin genes ensures the production of hemoglobin with appropriate oxygen-binding properties at each stage of human development, facilitating oxygen transport and homeostasis. Disruptions in this regulatory process can lead to various hemoglobinopathies, such as sickle cell disease and thalassemias.