To gain more insight into the regulatory mechanisms of trophoblast invasion, Bilban et al. investigated whole-genome gene expression profiles of nonmigratory villous cytotrophoblasts (CTBs) and invasive, extravillous trophoblasts (EVTs) purified from first trimester placentae and differentiating villous explant cultures, respectively. For microarray analysis, villous CTBs were purified from first trimester placentae and grown in culture for 24 hours, whereas EVTs were collected from first trimester villous explants seeded on Matrigel after 72 hours.
||first trimester extravillous trophoblasts
||first trimester villous cytotrophoblasts