Sanek Nicholas A, Grinblat Yevgenya
Department of Zoology, University of Wisconsin, Madison, WI 53706, USA.
Dev Biol. 2008 May 1;317(1):325-35. doi: 10.1016/j.ydbio.2008.02.029. Epub 2008 Mar 4.
Patterns of transcription factor expression establish a blueprint for the vertebrate forebrain early in embryogenesis. In the future diencephalon, several genes with patterned expression have been identified, yet their specific functions and interactions between them are not well understood. We have uncovered a crucial role for one such gene, zic2a, during formation of the anterior diencephalon in zebrafish. We show that zic2a is required for transcription of the prethalamic markers arx and dlx2a. This function is required during early steps of prethalamic development, soon after its specification. zic genes are evolutionarily related to glis, transcription factors that mediate hedgehog signaling. Intriguingly, the hedgehog signaling pathway also acts to promote development of the prethalamus. We asked if zic2a interacts with hedgehog signaling in the context of forebrain development in zebrafish. Our data show that hedgehog signaling and zic2a function at different times, and therefore act in parallel pathways during forebrain development. Taken together, our results identify Zic2a as a novel regulator of prethalamic development, and show that it functions independently of hedgehog signaling.
转录因子表达模式在胚胎发育早期为脊椎动物前脑建立了一个蓝图。在未来的间脑中，已经鉴定出几个具有模式化表达的基因，然而它们的具体功能以及它们之间的相互作用尚未得到很好的理解。我们在斑马鱼前间脑形成过程中发现了一个这样的基因——zic2a的关键作用。我们表明，zic2a是丘脑前标记物arx和dlx2a转录所必需的。该功能在丘脑前发育的早期阶段，即在其特化后不久就需要。zic基因在进化上与glis相关，glis是介导刺猬信号通路的转录因子。有趣的是，刺猬信号通路也起到促进丘脑前发育的作用。我们询问zic2a在斑马鱼前脑发育的背景下是否与刺猬信号通路相互作用。我们的数据表明，刺猬信号通路和zic2a在不同时间起作用，因此在前脑发育过程中通过平行途径发挥作用。综上所述，我们的结果确定Zic2a是丘脑前发育的一种新型调节因子，并表明它独立于刺猬信号通路发挥作用。
