Rentzsch Fabian, Guder Corina, Vocke Dirk, Hobmayer Bert, Holstein Thomas W
Zoological Institute, Darmstadt University of Technology, D-64287 Darmstadt, Germany.
Proc Natl Acad Sci U S A. 2007 Feb 27;104(9):3249-54. doi: 10.1073/pnas.0604501104. Epub 2007 Feb 20.
Signaling centers or organizers play a key role in axial patterning processes in animal embryogenesis. The function of most vertebrate organizers involves the activity of secreted antagonists of bone morphogenetic proteins (BMPs) such as Chordin or Noggin. Although BMP homologs have been isolated from many phyla, the evolutionary origin of the antagonistic BMP/Chordin system in organizer signaling is presently unknown. Here we describe a Chordin-like molecule (HyChdl) from Hydra that inhibits BMP activity in zebrafish embryos and acts in Hydra axis formation when new head organizers are formed during budding and regeneration. hychdl transcripts are also up-regulated in the head regeneration-deficient mutant strain reg-16. Accordingly, HyChdl has a function in organizer formation, but not in head differentiation. Our data indicate that the BMP/Chordin antagonism is a basic property of metazoan signaling centers that was invented in early metazoan evolution to set up axial polarity.
信号中心或组织者在动物胚胎发育的轴向模式形成过程中发挥着关键作用。大多数脊椎动物组织者的功能涉及分泌的骨形态发生蛋白（BMP）拮抗剂的活性，如脊索蛋白（Chordin）或头蛋白（Noggin）。尽管已从许多门中分离出BMP同源物，但组织者信号传导中拮抗BMP/脊索蛋白系统的进化起源目前尚不清楚。在这里，我们描述了一种来自水螅的类脊索蛋白分子（HyChdl），它在斑马鱼胚胎中抑制BMP活性，并在出芽和再生过程中形成新的头部组织者时参与水螅轴的形成。hychdl转录本在头部再生缺陷突变体菌株reg-16中也上调。因此，HyChdl在组织者形成中起作用，但在头部分化中不起作用。我们的数据表明，BMP/脊索蛋白拮抗作用是后生动物信号中心的一个基本特性，它是在后生动物早期进化中为建立轴向极性而产生的。
