Dorsoventral patterning of the vertebrate neural tube is conserved in a protochordate

Citations Over TimeTop 10% of 1997 papers

Abstract

The notochord and dorsal ectoderm induce dorsoventral compartmentalization of the vertebrate neural tube through the differential regulation of genes such as HNF-3beta, Pax3, Pax6 and snail. Here we analyze the expression of HNF-3beta and snail homologues in the ascidian, Ciona intestinalis, a member of the subphylum Urochordata, the earliest branch in the chordate phylum. A combination of in situ hybridization and promoter fusion analyses was used to demonstrate that the Ciona HNF-3beta homologue is expressed in the ventralmost ependymal cells of the neural tube, while the Ciona snail homologue is expressed at the junction between the invaginating neuroepithelium and dorsal ectoderm, similar to the patterns seen in vertebrates. These findings provide evidence that dorsoventral compartmentalization of the chordate neural tube is not an innovation of the vertebrates. We propose that precursors of the floor plate and neural crest were present in a common ancestor of both vertebrates and ascidians.

Related Papers

• → Delayed formation of the floor plate after ablation of the avian notochord(1993)66 cited
• → Dual origin of the floor plate in the avian embryo(2002)52 cited
• → Early Stages of Notochord and Floor Plate Development in the Chick Embryo Defined by Normal and Induced Expression of HNF-3β(1995)117 cited
• → Evolution of Developmental Programs for the Midline Structures in Chordates: Insights From Gene Regulation in the Floor Plate and Hypochord Homologues of Ciona Embryos(2021)8 cited
• → Polarity and Patterning in the Neural Tube: The Origin and Function of the Floor Plate(2007)75 cited