FIG. 7.
HIF-deficient trophoblasts adopt aberrant cell fates in vitro. (A) Arnt+/+ and Arnt−/− TS cells were differentiated under 20% and 3% O2 and examined by Northern blot for expression of a spongiotrophoblast marker (Mash2), TGC-specific genes (Proliferin and Hand1), and labyrinthine trophoblast markers (TFEB and GCM1). (B) Hif1α+/+ Hif2α+/+ and Hif1α−/− Hif2α−/− TS cells were differentiated for 4 days under 20% and 3% O2 and examined by Northern blot for expression of TFEB and Hand1. The lower panel shows TFEB expression after 5 days of differentiation for Hif1α+/+ Hif2α+/+ and Hif1α−/− Hif2α−/− TS cells. (C) Quantitative real-time PCR (Q-PCR) for the spongiotrophoblast gene Mash2 and the syncytiotrophoblast genes TFEB and GCM1. A second Arnt−/− TS line (no. 2) was added to these experiments to demonstrate that these phenotypes are due to HIF deficiency and are associated with multiple independent lines. U, undifferentiated cells; D, differentiated cells.