Kemp Caroline, Willems Erik, Abdo Shaaban, Lambiv Louis, Leyns Luc
Vrije Universiteit Brussel, Lab for Cell Genetics, Brussels, Belgium.
Dev Dyn. 2005 Jul;233(3):1064-75. doi: 10.1002/dvdy.20408.
In this extensive study, real-time reverse transcriptase-polymerase chain reaction was used to analyze the expression levels of all 19 Wnt genes and their 11 potential antagonists in mouse blastocysts, pregastrula, gastrula, and neurula stages. By complementing these results with in situ hybridization, we revealed new expression domains for Wnt2b and Sfrp1, respectively, in the future primitive streak at the posterior side and in the anterior visceral endoderm before the initiation of gastrulation. Moreover, the anterior visceral endoderm expresses three secreted Wnt antagonists (Sfrp1, Sfrp5, and Dkk1) in partially overlapping domains. We also identified expression patterns for the Wnt1, Wnt3a, Wnt6, Wnt7b, Wnt9a, Wnt10b, and Sfrp1 genes at the blastocyst stage. In particular, the expression of Wnt1 and Sfrp1 predominantly in the inner cell mass and of Wnt9a in the mural trophoblast and inner cell mass cells surrounding the blastocoele suggests new roles for the Wnt pathway in preimplantation development. This article is the first report on the regional expression of Wnt genes in the mouse blastocyst.
在这项广泛的研究中，采用实时逆转录聚合酶链反应分析了小鼠囊胚、原肠胚前期、原肠胚和神经胚阶段所有19个Wnt基因及其11种潜在拮抗剂的表达水平。通过原位杂交对这些结果进行补充，我们分别揭示了Wnt2b和Sfrp1在未来原条后侧以及原肠胚形成起始前的前内脏内胚层中的新表达区域。此外，前内脏内胚层在部分重叠区域表达三种分泌型Wnt拮抗剂（Sfrp1、Sfrp5和Dkk1）。我们还确定了Wnt1、Wnt3a、Wnt6、Wnt7b、Wnt9a、Wnt10b和Sfrp1基因在囊胚阶段的表达模式。特别是，Wnt1和Sfrp1主要在内细胞团中表达，而Wnt9a在围绕囊胚腔的壁滋养层和内细胞团细胞中表达，这表明Wnt信号通路在植入前发育中具有新的作用。本文是关于小鼠囊胚中Wnt基因区域表达的首次报道。
