Expression and Cellular Localization of Psx Gene in Rat Placenta / 체질인류학회지

ABSTRACT

Homeobox genes seem to play critical roles in regulating morphogenesis, patterning, organogenesis, and differentiation. They have the conserved sequence that codes the DNA-binding domain called homeodomain. The expression and cellular localization of rPsx mRNA in rat placenta during placental development were examined by in situ hybridization histochemistry at different embryonic stages (Embryonic days 7.5~16.5). rPsx mRNA was first detected in chorionic ectoderm of placenta at E 10.5. This transcript was localized in labyrinth trophoblast and trophoblast giant cells at E 11.5. Hybridization signals were observed in labyrinth trophoblast, spongiotrophoblast, and trophoblast giant cells at E 12.5, E 13.5, and E 14.5. At E 15.5, hybridization signal was detected in labyrinth trophoblast and spongiotrophoblast but not in trophoblast giant cells. Hybridization signal was only detected in labyrinth trophoblast at E 16.5. rPsx mRNA was not detected in decidua and any tissues of the embryo from E 7.5 to E 9.5 of gestations. From these results, a new rPsx homeobox gene is first expressed at E 10.5 and detected in chorionic ectoderm, labyrinth trophblast, spongiotrophoblast and trophoblast giant cells of the placenta. This gene may play a critical role in differentiation and development of trophoblast cells.