Greb1 is required for axial elongation and segmentation in vertebrate embryos

This study presents transcription profiles for mouse axial progenitors, presomitic mesoderm and tailbud mesoderm. During vertebrate embryonic development, the formation of axial structures is driven by a population of stem-like cells (axial progenitors) that reside in a region of the tailbud called the chordoneural hinge (CNH) where. We have compared the CNH transcriptome with those of surrounding tissues and shown that the CNH and tailbud mesoderm are transcriptionally similar, and distinct from the presomitic mesoderm. Amongst CNH-enriched genes are several that are required for axial elongation, including Wnt3a, Cdx2, Brachyury/T and Fgf8, and androgen/estrogen receptor nuclear signalling components such as Greb1. Chordoneural hinge, tailbud mesoderm, and presomitic mesoderm were dissected from E10.5 wildtype mouse embryos. These microdissected tissues were used to extract total RNA for microarray study.本研究提供了小鼠轴系祖细胞（axial progenitors）、体节前中胚层（presomitic mesoderm）以及尾芽中胚层（tailbud mesoderm）的转录谱。在脊椎动物胚胎发育过程中，轴系结构的形成由一群定位于尾芽内称为脊索神经铰链（chordoneural hinge, CNH）的干细胞样细胞驱动。本研究将脊索神经铰链的转录组与周围组织的转录组进行比对，结果显示脊索神经铰链与尾芽中胚层在转录水平上具有相似性，且与体节前中胚层存在显著差异。在脊索神经铰链富集的基因中，包含多个轴系伸长所必需的基因，包括Wnt3a、Cdx2、Brachyury/T以及Fgf8，同时还包括雄激素/雌激素受体核信号通路相关组分Greb1。本研究从E10.5野生型小鼠胚胎中显微分离了脊索神经铰链、尾芽中胚层以及体节前中胚层，利用这些显微切割得到的组织提取总RNA，用于基因芯片（microarray）研究。