Regionalized nervous system in Hydra and the mechanism of its development

In this study we show how it is formed and maintained, focusing on the neuropeptide Hym-176 gene and its paralogs. First, we demonstrate that four axially localized neuron subsets that express different combination of the neuropeptide Hym-176 gene and its paralogs cover almost an entire body, forming a regionalized nervous system in Hydra. Second, we show that positional information governed by the Wnt signaling pathway plays a key role in determining the regional specificity of the neuron subsets as is the case in bilaterians. Finally, we demonstrated two basic mechanisms, regionally restricted new differentiation and phenotypic conversion, both of which are in part conserved in bilaterians, are involved in maintaining boundaries between the neuron subsets. Therefore, this study is the first comprehensive analysis of the anatomy and developmental regulation of the divergently evolved and axially regionalized peptidergic nervous system in Hydra, implicating an ancestral origin of neural regionalization.Graphical abstract

Source: Gene Expression Patterns - January 23, 2019 Category: Genetics & Stem Cells Source Type: research