Mdecular Mechanism of Oogenesis-Assisted Reproductive Technology and genomic imprinting-

为了了解辅助生殖技术如何影响人类早期发育过程中的表观遗传变化，我们将母体血浆和脐带血中的游离细胞DNA和RNA作为解决这一问题的关键工具。首先，用CA重复标记分析了3例父系限制性胎盘嵌合体（三体来自父系）。在所有三个病例中，在母体血浆中检测到父系遗传的额外等位基因，但在胎儿中未检测到，这表明无细胞DNA来自胎盘（Masuzaki J Med Genetics 2004）。此外，我们使用8个高度多态性标记在日本人的脐带血中检测母体DNA。阴道分娩的脐带血中母体DNA的检出率明显高于剖宫产，表明分娩增加了脐带血中母体DNA的污染（Masuzaki等）。临床化学，2004)。其次，选择hCG和hPL基因作为胎盘表达基因。采用实时定量RT-PCR技术，检测母体血浆中这两种mRNA的浓度随胎龄的变化。然后，我们将该技术应用于胎盘状态的评估与前置胎盘-percreta（临床化学，在出版社）的情况下。在这个项目（15591761）中，我们为我们的知识增加了三个新的发现。以下三个新发现表明，胎盘印迹基因表达是评估表观遗传状态的一个靶标。1)母体血浆中游离细胞DNA来自胎盘；2)存在双向输血，且至少受产程影响；3)母体血浆中胎盘mRNA可能是了解胎盘状态的靶标。因此，我们有线索了解辅助生殖技术如何影响早期人类发育过程中的表观遗传变化。

To know how assisted reproductive technology affects on the epigenetic change during early human development, we aimed at the cell free DNA and RNA in maternal plasma and cord blood as the key tool to resolve this question.First, three cases with paternal confined placental mosaicism (trisomy is from paternal origin) were analyzed by using CA repeats markers. In all three cases, paternal transmitted extra-alleles were detected in maternal plasma, but not in fetus, suggesting that cell free DNA is from placenta (Masuzaki J Med Genetics 2004).Also, we detected maternal DNA in cord blood using 8 highly polymorphic markers in Japanese. Detection rate of maternal DNA in cord blood was significantly higher in cases with vaginal delivery than in cases with Cesarean Section, indicating that labor increases maternal DNA contamination in cord blood (Masuzaki et al. Clin Chemi 2004).Second, hCG and hPL genes were selected as genes expressed from placenta. By using real time quantitative RT-PCR, changing concentration of both mRNA in maternal plasma was measured as the progress of gestational age. And then, we applied this technique to the evaluation of placental status in a case with placenta previa-percreta (Clin Chemi, in press).In this project(15591761), we add three novel findings to our knowledge. Three novel findings are below and suggested that imprinting gene expressed from placenta is a target to evaluate the epigenetic status. 1)Cell free DNA in maternal plasma is from placenta, 2)Bidirectional blood transfusion exists and this is affected by labor at least, and 3)there is the possibility that placental mRNA in maternal plasma is a target to know the placental status.Therefore, we got a clue to know how assisted reproductive technology affects on the epigenetic change during early human development.