RRC ID 47661
著者 Abitua PB, Gainous TB, Kaczmarczyk AN, Winchell CJ, Hudson C, Kamata K, Nakagawa M, Tsuda M, Kusakabe TG, Levine M.
タイトル The pre-vertebrate origins of neurogenic placodes.
ジャーナル Nature
Abstract The sudden appearance of the neural crest and neurogenic placodes in early branching vertebrates has puzzled biologists for over a century. These embryonic tissues contribute to the development of the cranium and associated sensory organs, which were crucial for the evolution of the vertebrate "new head". A previous study suggests that rudimentary neural crest cells existed in ancestral chordates. However, the evolutionary origins of neurogenic placodes have remained obscure owing to a paucity of embryonic data from tunicates, the closest living relatives to those early vertebrates. Here we show that the tunicate Ciona intestinalis exhibits a proto-placodal ectoderm (PPE) that requires inhibition of bone morphogenetic protein (BMP) and expresses the key regulatory determinant Six1/2 and its co-factor Eya, a developmental process conserved across vertebrates. The Ciona PPE is shown to produce ciliated neurons that express genes for gonadotropin-releasing hormone (GnRH), a G-protein-coupled receptor for relaxin-3 (RXFP3) and a functional cyclic nucleotide-gated channel (CNGA), which suggests dual chemosensory and neurosecretory activities. These observations provide evidence that Ciona has a neurogenic proto-placode, which forms neurons that appear to be related to those derived from the olfactory placode and hypothalamic neurons of vertebrates. We discuss the possibility that the PPE-derived GnRH neurons of Ciona resemble an ancestral cell type, a progenitor to the complex neuronal circuit that integrates sensory information and neuroendocrine functions in vertebrates.
巻・号 524(7566)
ページ 462-5
公開日 2015-8-11
DOI 10.1038/nature14657
PII nature14657
PMID 26258298
PMC PMC5008972
MeSH Animals Body Patterning Bone Morphogenetic Proteins Ciona intestinalis / cytology* Ciona intestinalis / embryology* Ciona intestinalis / genetics Ciona intestinalis / metabolism Ectoderm / metabolism Gonadotropin-Releasing Hormone / metabolism HEK293 Cells Homeodomain Proteins / metabolism Humans Intracellular Signaling Peptides and Proteins / metabolism Larva / cytology Larva / metabolism Molecular Sequence Data Neurons / cytology* Neurons / metabolism Protein Tyrosine Phosphatases / metabolism Receptors, G-Protein-Coupled / metabolism Vertebrates / anatomy & histology* Vertebrates / embryology* Vertebrates / physiology
IF 40.137
引用数 15
カタユウレイボヤ・(ニッポンウミシダ) Wild C. int