A gene regulatory network for apical organ neurogenesis and its spatial control in sea star embryos
| Autor: | Veronica F. Hinman, Kristen A. Yankura, Alys M. Cheatle Jarvela |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Embryo Nonmammalian Neurogenesis Ectoderm Biology Serotonergic Nervous System Animals Genetically Modified Starfish 03 medical and health sciences 0302 clinical medicine medicine Animals Gene Regulatory Networks Progenitor cell Molecular Biology Gene Cells Cultured 030304 developmental biology Body Patterning 0303 health sciences Gene Expression Regulation Developmental Cell Differentiation Embryo Anatomy Neural stem cell Cell biology 030104 developmental biology medicine.anatomical_structure Neuron Developmental biology 030217 neurology & neurosurgery Serotonergic Neurons Developmental Biology |
| Zdroj: | Development. |
| ISSN: | 1477-9129 0950-1991 |
| Popis: | How neural stem cells generate the correct number and type of differentiated neurons in appropriate places is an important question in developmental biology. Although nervous systems are diverse across phyla, many taxa have a larva that forms an anterior concentration of serotonergic neurons, or apical organ. The number of neurons in these organs is highly variable. Previous work demonstrated that the sea star embryo initially has a pan-neurogenic ectoderm, but the genetic mechanism that directs only a subset of these cells to generate serotonergic neurons in a particular location had not been resolved. Here, we show that neurogenesis in the sea star larvae begins with soxc-expressing multipotent progenitors. These give rise to restricted progenitors that express lhx2/9. Soxc- and lhx2/9-expressing cells are capable of undergoing both asymmetric divisions, which allow for progression towards a particular neural fate, and symmetric proliferative divisions. Importantly, we show that nested concentric domains of gene expression along the anterior-posterior (AP) axis, which have been observed in a great diversity of metazoans, control neurogenesis in the sea star larva by promoting particular division modes and progression towards becoming a neuron. This work, therefore, explains how spatial patterning in the ectoderm controls progression of neurogenesis in addition to providing spatial cues for proper neuron location. Modification to the sizes of these AP territories provides a simple mechanism to explain the diversity of neuron number found among apical organs. |
| Databáze: | OpenAIRE |
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