title: Pdm and Castor specify late-born motor neuron identity in the NB7-1 lineage.
abstract: Embryonic development requires generating cell types at the right place (spatial patterning) and the right time (temporal patterning). Drosophila neuroblasts undergo stem cell-like divisions to generate an ordered sequence of neuronal progeny, making them an attractive system to study temporal patterning. Embryonic neuroblasts sequentially express Hunchback, Krüppel, Pdm1/Pdm2 (Pdm), and Castor (Cas) transcription factors. Hunchback and Krüppel specify early-born temporal identity, but the role of Pdm and Cas in specifying temporal identity has never been addressed. Here we show that Pdm and Cas regulate late-born motor neuron identity within the NB7-1 lineage: Pdm specifies fourth-born U4 motor neuron identity, while Pdm/Cas together specify fifth-born U5 motor neuron identity. We conclude that Pdm and Cas specify late-born neuronal identity; that Pdm and Cas act combinatorially to specify a temporal identity distinct from either protein alone, and that Cas repression of pdm expression regulates the generation of neuronal diversity.
authors.affiliation: Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, 97403, USA.
authors.forename: Ruth
authors.initials: R
authors.lastname: Grosskortenhaus
authors.forename: Kristin J
authors.initials: KJ
authors.lastname: Robinson
authors.forename: Chris Q
authors.initials: CQ
authors.lastname: Doe
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D019521:Body Patterning; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004330:Drosophila / Q000166:cytology / Q000196:embryology* / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D018398:Homeodomain Proteins / Q000235:genetics*; D009046:Motor Neurons / Q000166:cytology* / Q000378:metabolism; D050809:POU Domain Factors / Q000235:genetics*; D010641:Phenotype
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D050809:POU Domain Factors; C110593:cas protein, Drosophila; C104121:nub protein, Drosophila; C072851:pdm2 protein, Drosophila