Monsoro-Burq A, Le Douarin N M
Institut d'Embryologie Cellulaire et Moléculaire, FRE 2160, 49 bis avenue de la Belle Gabrielle, 94736 Nogent-sur-Marne Cedex, France.
Mol Cell. 2001 Apr;7(4):789-99. doi: 10.1016/s1097-2765(01)00223-4.
In chick embryos, the first signs of left-right asymmetry are detected in Hensen's node, essentially by left-sided Sonic Hedgehog (Shh) expression. After a gap of several hours, SHH induces polarized gene activities in the left paraxial mesoderm. We show that during this time period, BMP4 signaling is necessary and sufficient to maintain Shh asymmetry within the node. SHH and BMP4 proteins negatively regulate each other's transcription, resulting in a strict complementarity between these two gene patterns on each side of the node. Noggin, present in the midline at this stage, limits BMP4 spreading. Moreover, BMP4 is downstream to Activin signals and controls Fgf8. Thus, early BMP4 signaling coordinates left and right pathways in Hensen's node.
在鸡胚中，左右不对称的最初迹象在亨氏结中被检测到，主要是通过左侧的音猬因子（Shh）表达。在间隔数小时后，SHH诱导左侧近轴中胚层中的极化基因活性。我们表明，在此时间段内，骨形态发生蛋白4（BMP4）信号对于维持结内Shh的不对称性是必要且充分的。SHH和BMP4蛋白相互负调控对方的转录，导致结两侧这两种基因模式之间形成严格的互补性。在此阶段中线处存在的头蛋白（Noggin）限制BMP4的扩散。此外，BMP4位于激活素信号下游并控制成纤维细胞生长因子8（Fgf8）。因此，早期BMP4信号协调亨氏结中的左右通路。
