Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun 130062, China.
Anim Reprod Sci. 2013 Jun;139(1-4):101-8. doi: 10.1016/j.anireprosci.2013.04.008. Epub 2013 Apr 19.
The aberrant expression of imprinted genes induces parthenogenetic fetal and placental dysplasia, thus leading to failures in embryonic development. Igf2 and H19 are co-expressed in endoderm and mesoderm-derived tissues and play an important role in normal embryo and extraembryonic development. In this study, the expression and methylation of Igf2/H19 in porcine parthenogenetic fetuses and placentas which had grown 28 days was examined first time to further characterize mammalian parthenogenesis. Weight and morphological comparisons were conducted between parthenogenetic embryos on Day 28 and normal fertilized embryos (control). The results indicated that parthenogenetic fetuses and placentas had smaller weights and volumes than those of the control. In addition, quantitative RT-PCR (qRT-PCR) analysis was performed to determine Igf2/H19 expression levels, showing that the expression of H19 was up-regulated, while Igf2 expression was almost undetectable in both parthenogenetic fetuses and placentas. As a potential mechanism underlying this disrupted expression, the methylation of Igf2/H19 DMR3 was detected using bisulfite sequencing PCR analysis, which revealed the significant hypomethylation of DMR3 in parthenogenetic fetuses and placentas. These results suggest that disruption of Igf2/H19 expression in parthenogenetic fetuses and placentas contributes to implantation failure and/or abortion in swine parthenogenesis, which might be associated with differential methylation patterns in the imprinting control region of imprinted genes.
印迹基因的异常表达会导致孤雌生殖胎儿和胎盘的发育不良，从而导致胚胎发育失败。Igf2 和 H19 在内胚层和中胚层衍生组织中共同表达，在正常胚胎和胚胎外发育中发挥重要作用。在这项研究中，首次检查了在 28 天生长的猪孤雌生殖胎儿和胎盘中的 Igf2/H19 的表达和甲基化情况，以进一步表征哺乳动物孤雌生殖。对第 28 天的孤雌胚胎和正常受精胚胎（对照）进行重量和形态比较。结果表明，孤雌胎儿和胎盘的重量和体积均小于对照。此外，还进行了定量 RT-PCR（qRT-PCR）分析以确定 Igf2/H19 的表达水平，结果表明 H19 的表达上调，而 Igf2 在孤雌胎儿和胎盘中的表达几乎检测不到。作为这种异常表达的潜在机制，使用亚硫酸氢盐测序 PCR 分析检测了 Igf2/H19 DMR3 的甲基化，结果表明孤雌胎儿和胎盘中的 DMR3 显著去甲基化。这些结果表明，孤雌生殖胎儿和胎盘中 Igf2/H19 表达的破坏导致猪孤雌生殖中的植入失败和/或流产，这可能与印迹基因印迹控制区的差异甲基化模式有关。
