Figure 4

A schematic representation of lactogenic hormone profiles during pregnancy in the mouse or rat. Early pregnancy is dominated by the twice-daily surges of PRL produced by the maternal anterior pituitary; midgestation by the products of three PL-I genes; and the second half of gestation by PL-II. The fetal anterior pituitary begins producing PRL at the end of pregnancy. Abbreviations: PRL, prolactin, PL-Is, placental lactogen-Iα, β, γ; PL-II, placental lactogen-II.