title: Specification of neuronal subtypes by different levels of Hunchback.
abstract: During the development of the central nervous system, neural progenitors generate an enormous number of distinct types of neuron and glial cells by asymmetric division. Intrinsic genetic programs define the combinations of transcription factors that determine the fate of each cell, but the precise mechanisms by which all these factors are integrated at the level of individual cells are poorly understood. Here, we analyzed the specification of the neurons in the ventral nerve cord of Drosophila that express Crustacean cardioactive peptide (CCAP). There are two types of CCAP neurons: interneurons and efferent neurons. We found that both are specified during the Hunchback temporal window of neuroblast 3-5, but are not sibling cells. Further, this temporal window generates two ganglion mother cells that give rise to four neurons, which can be identified by the expression of empty spiracles. We show that the expression of Hunchback in the neuroblast increases over time and provide evidence that the absolute levels of Hunchback expression specify the two different CCAP neuronal fates.
authors.affiliation: Centro de Biología Molecular-Severo Ochoa (CSIC-UAM), c./Nicolás Cabrera 1, Universidad Autónoma, Madrid 28049, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Moris-Sanz
authors.affiliation: Centro de Biología Molecular-Severo Ochoa (CSIC-UAM), c./Nicolás Cabrera 1, Universidad Autónoma, Madrid 28049, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Estacio-Gómez
authors.affiliation: Centro de Biología Molecular-Severo Ochoa (CSIC-UAM), c./Nicolás Cabrera 1, Universidad Autónoma, Madrid 28049, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Alvarez-Rivero
authors.affiliation: Centro de Biología Molecular-Severo Ochoa (CSIC-UAM), c./Nicolás Cabrera 1, Universidad Autónoma, Madrid 28049, Spain diazbenjumea@cbm.csic.es.
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Díaz-Benjumea
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D002454:Cell Differentiation / Q000502:physiology*; D002490:Central Nervous System / Q000166:cytology / Q000196:embryology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009479:Neuropeptides; D014157:Transcription Factors; C058620:crustacean cardioactive peptide; C061245:hb protein, Drosophila; D001973:Bromodeoxyuridine
keywords: Bursicon; CCAP; Cell fate specification; Central nervous system; Drosophila; Hunchback; Temporal identity factors