Control of Hemoglobin Synthesis in Fetal Erythroid Cells by L‐Thyroxine

Fetal mouse liver cells were incubated in the presence of L‐thyroxine. Globin synthesis by cells from the 13th to 15th days of gestation was stimulated by the presence of the hormone. Although protein synthesis by cells from the 17th day of gestation was stimulated, the protein was not identified as globin. A tentative conclusion was drawn that fetal erythroid tissue may be preferentially stimulated by thyroid hormone.