Illes Jean C, Winterbottom Emily, Isaacs Harry V
Department of Biology, University of York, York, United Kingdom.
Dev Dyn. 2009 Jan;238(1):194-203. doi: 10.1002/dvdy.21816.
Gsx class proteins are members of the ParaHox homeodomain transcription factor family with conserved roles in specification and patterning of the nervous system. We report the cloning of two Gsx genes, Gsh1 and Gsh2, from the frog Xenopus tropicalis. We demonstrate the existence of a single, intact Xenopus ParaHox cluster, containing Gsh1, Pdx, and Cdx2, plus three degenerate clusters containing Gsh2, Cdx1, and Cdx4. Anterior expression boundaries of genes from the intact ParaHox cluster are co-linear with respect to their genomic organization. We show that Gsh1 and Gsh2 exhibit complex, overlapping patterns of expression within the anterior nervous system from open neural plate stages. We also find that expression of Gsh2, Nkx6, and Msx1 across the medio-lateral axis of the amphibian neural plate is strikingly similar to that of related genes in the Drosophila neuroectoderm. These findings provide further evidence for a conserved pathway regulating dorso-ventral patterning in the Bilateria.
Gsx类蛋白是副同源盒基因家族的成员，在神经系统的特化和模式形成中发挥着保守作用。我们报道了从热带爪蟾中克隆出两个Gsx基因，即Gsh1和Gsh2。我们证明了存在一个单一的、完整的爪蟾副同源盒基因簇，包含Gsh1、Pdx和Cdx2，以及三个包含Gsh2、Cdx1和Cdx4的退化基因簇。完整副同源盒基因簇中基因的前侧表达边界与其基因组组织是共线的。我们发现，从开放神经板阶段开始，Gsh1和Gsh2在前侧神经系统中呈现出复杂且重叠的表达模式。我们还发现，Gsh2、Nkx6和Msx1在两栖类神经板的中侧轴上的表达与果蝇神经外胚层中相关基因的表达惊人地相似。这些发现为两侧对称动物中调节背腹模式形成保守途径提供了进一步的证据。
