Laboratory of Molecular Genetics, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Biochem Biophys Res Commun. 2010 Nov 26;402(4):626-30. doi: 10.1016/j.bbrc.2010.10.070. Epub 2010 Oct 28.
Coordinated Nodal-related signals and Bozozok (Boz) activity are critical for the initial specification of dorsal mesoderm and anterior neuroectoderm during zebrafish embryogenesis. Overexpression of Boz expands gsc expression into the ventro-lateral marginal blastomeres where Nodal signaling is active, but is insufficient to induce ectopic gsc expression in the animal region. We found that overexpression of Boz together with depletion of Lnx-2b (previously named Lnx-like, Lnx-l), but not each manipulation alone, causes robust gsc expression in all blastomeres. Furthermore, nodal-related signals are required for gsc expression in embryos with elevated Boz activity. Through targeted injection into single cells at the 128-cell stage we illustrate the role of maternally deposited Lnx-2b to restrict the expansion of gsc expression into the presumptive ectodermal region. This report provides a novel mechanism for limiting dorsal organizer specification to a defined region of the early zebrafish embryo.
协调的节点相关信号和 Bozozok（Boz）活性对于斑马鱼胚胎发生过程中背侧中胚层和前神经外胚层的初始特化至关重要。 Boz 的过表达将 gsc 表达扩展到 Nodal 信号活跃的腹侧边缘裂球中，但不足以在动物区域诱导异位 gsc 表达。我们发现，Boz 的过表达与 Lnx-2b（以前称为 Lnx-like，Lnx-l）的耗尽一起，但不是单独的操作，会导致所有裂球中 gsc 表达的强烈增加。此外，在 Boz 活性升高的胚胎中，节点相关信号对于 gsc 表达是必需的。通过在 128 细胞阶段靶向注射单个细胞，我们说明了母源沉积的 Lnx-2b 对限制 gsc 表达扩展到假定的外胚层区域的作用。本报告为限制早期斑马鱼胚胎中背侧组织者特化到特定区域提供了一种新的机制。
