title: Nkx2.2+ progenitors generate somatic motoneurons in the chick spinal cord.
abstract: Heterogeneous classes of neurons are present in the spinal cord and are essential for its function. Expression patterns of transcription factors in neural progenitor cells determine neuron subtypes during development. Nkx2.2 is expressed in the progenitor cell pool located just ventrally to the Olig2-positive pool and is indispensable for V3 interneuron generation in the spinal cord and also for visceral motoneuron generation in the hindbrain. However, whether Nkx2.2-positive progenitor cells generate diverse classes of neuron is not fully understood. Using a chick lineage tracing method in a genetically-defined manner, we found that Nkx2.2-expressing progenitor cells differentiate into general visceral motoneurons as well as sim1-positive V3 interneurons. Surprisingly, we further observed that Nkx2.2-expressing progenitors differentiate into somatic motoneuron. Our findings suggest that the different classes of motoneurons are derived from more complex sources than were previously expected in the chick spinal cord.
authors.affiliation: Department of Biology, Kyoto Prefectural University of Medicine, Kyoto, Japan. hgotoh@koto.kpu-m.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Gotoh
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ono
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nomura
authors.forename: Hirohide
authors.initials: H
authors.lastname: Takebayashi
authors.forename: Hidekiyo
authors.initials: H
authors.lastname: Harada
authors.forename: Harukazu
authors.initials: H
authors.lastname: Nakamura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ikenaka
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D002642:Chick Embryo; D018507:Gene Expression Regulation, Developmental; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D019426:Integrases / Q000378:metabolism; D007395:Interneurons / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D009046:Motor Neurons / Q000166:cytology* / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D013116:Spinal Cord / Q000166:cytology* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D029961:Zebrafish Proteins
chemical_list: D015220:Calcium Channels; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; C000715627:Nkx2-2 protein, mouse; D050916:TRPV Cation Channels; D014157:Transcription Factors; C446923:Trpv6 protein, mouse; D029961:Zebrafish Proteins; C000715630:nkx2.2b protein, zebrafish; C045073:Cre recombinase; D019426:Integrases