Expression profile for marker genes during trophoblast stem cell (TSC) differentiation. To analyze trophoblast lineage formation, each two Cx31.1+/− and Cx31.1−/− TSC lines were differentiated for 10 days. Gene expression was analyzed by quantitative PCR and graphed as relative expression levels (fold change) over time. The analyzed marker genes show a block in terminal TGC and syncytiotrophoblast differentiation in the Cx31.1−/− TSC lines. In the Cx31.1−/− TSC lines induction of Tpbpa
(A) expression is delayed compared with controls. Subsequently, expression of the secondary TGC markers Prl3b1/Pl-2
(D) and Ctsq
(E) is delayed and expression levels remain below those of Cx31.1+/− controls. Also, Cx31.1−/− TSC exhibit a delayed and reduced expression of Prl3d1/Pl-1
(B) and Prl2c/Plf
(C) TGC markers, and Cdkn1c
(F), mediating cell cycle arrest and endoreduplication, reveals a slight shift in Cx31.1−/− TSC lines. Syncytiotrophoblast marker genes Gjb2/Cx26
(G) and Syna (H) are reduced in Cx31.1−/− TSC, indicating inhibition in of labyrinthine trophoblast differentiation.