Fig. 4.

JAK1 Plays an Essential Role in Trophoblast Giant Cell Differentiation

A, In JAK1-deficient placentas, the size and number of trophoblast giant cells were decreased. B, The number of trophoblast giant cells was significantly reduced in JAK-1 deficient placentas. C, The expression of the stem cell marker 4311 in the spongiotrophoblast layer was markedly enhanced in JAK1-deficient placentas. D, The abnormality in the SOCS3-deficient placentas was restored in mice with the JAK1+/− or −/− back ground. The placentas at term (E18.5) are shown in the case of the mice with SOCS3−/−, JAK1+/+ (E12.5). E, Viable SOCS3−/− embryos were detected at term (E18.5) in the JAK1+/− or −/− background, clearly indicating the functional rescue of SOCS3-deficient placentas. de, Decidva; gi, trophoblast giant cells; sp, spongiotrophoblast layer; la, labyrinthine layer.