Paternal uniparental disomy 14 and related conditions: Placental expression analyses and histological examination

点击翻译按钮获取中文摘要

We performed placental study of two cases with UPD(14)pat and a case with maternal microdeletion involving DLK1, DMRs and MEG3. RTL1 and DLK1 expressed only in endothelial cells of villous vessels. In the placentas of UPD(14)pat revealing placentomegaly, the expression of DLK1 and RTL1 increased, even though in the placenta of a case with microdeletion revealing placentomegaly, only the expression of RTL1 increased. Electron microscopic study showed hyperplasia of the endothelial cells and the pericytes in the placentas of UPD(14)pat. Expression analysis using placentas of UPD(14)pat showed excessive RTL1 expression above the normal control levels because of a synergic effect between the biallelic activation of RTL1 and loss of functional microRNA in RTL1as as a repressor for RTL1. These results indicate that excessive RTL1 expression causes placentomegaly and RTL1 expression is regulated through an RNAi mechanism. RTL1 may play an essential role in the development of human placenta.