title: A new role of Klumpfuss in establishing cell fate during the GMC asymmetric cell division.
abstract: Studies in the Drosophila embryonic NB4-2 lineage have suggested that the transcription factor Klumpfuss (Klu) functions within embryonic neuroblast lineages to differentiate between the identities of two adjacent ganglion mother cells (GMCs). However, because of the limited lineage markers available, these observations have been made only for the NB4-2 lineage. Recent findings have placed this transcription factor in the vanguard of Drosophila neural stem cell biology by demonstrating that Klu is necessary for larval neuroblast growth and self-renewal. Here, we have studied the role of klu in an incipient model in order to address basic mechanisms of neural specification: the Va system. None of the previously reported roles of Klu satisfactorily explain our observations. Unexpectedly, in this lineage, klu is necessary for differentiating between the fates of the two neurons born from a unique GMC; klu mutants produce two B-type cells, rather than one B-type (Notch-OFF) and one A-type (Notch-ON) cell. Additionally, our results demonstrate that Klu operates in the GMC and/or in the newly born neuron, but not in the neuroblast. Unlike in larval neuroblasts in which Klu is an executor of Notch signaling, we have found that Klu does not lie downstream of the Notch pathway in this cell division context.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain.
authors.forename: Hugo
authors.initials: H
authors.lastname: Gabilondo
authors.forename: María
authors.initials: M
authors.lastname: Losada-Pérez
authors.forename: Ignacio
authors.initials: I
authors.lastname: Monedero
authors.forename: Arturo
authors.initials: A
authors.lastname: Torres-Herráez
authors.forename: Isabel
authors.initials: I
authors.lastname: Molina
authors.forename: Laura
authors.initials: L
authors.lastname: Torroja
authors.forename: Jonathan
authors.initials: J
authors.lastname: Benito-Sipos
mesh_terms: D000818:Animals; D017209:Apoptosis; D060049:Asymmetric Cell Division; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000378:metabolism*; D017952:Ganglia, Invertebrate / Q000166:cytology* / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C107732:Klu protein, Drosophila; D051880:Receptors, Notch; D014157:Transcription Factors