title: Temporal patterning of Drosophila medulla neuroblasts controls neural fates.
abstract: In the Drosophila optic lobes, the medulla processes visual information coming from inner photoreceptors R7 and R8 and from lamina neurons. It contains approximately 40,000 neurons belonging to more than 70 different types. Here we describe how precise temporal patterning of neural progenitors generates these different neural types. Five transcription factors-Homothorax, Eyeless, Sloppy paired, Dichaete and Tailless-are sequentially expressed in a temporal cascade in each of the medulla neuroblasts as they age. Loss of Eyeless, Sloppy paired or Dichaete blocks further progression of the temporal sequence. We provide evidence that this temporal sequence in neuroblasts, together with Notch-dependent binary fate choice, controls the diversification of the neuronal progeny. Although a temporal sequence of transcription factors had been identified in Drosophila embryonic neuroblasts, our work illustrates the generality of this strategy, with different sequences of transcription factors being used in different contexts.
authors.affiliation: Department of Biology, New York University, 100 Washington Square East, New York, New York 10003, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Ted
authors.initials: T
authors.lastname: Erclik
authors.forename: Claire
authors.initials: C
authors.lastname: Bertet
authors.forename: Zhenqing
authors.initials: Z
authors.lastname: Chen
authors.forename: Roumen
authors.initials: R
authors.lastname: Voutev
authors.forename: Srinidhi
authors.initials: S
authors.lastname: Venkatesh
authors.forename: Javier
authors.initials: J
authors.lastname: Morante
authors.forename: Arzu
authors.initials: A
authors.lastname: Celik
authors.forename: Claude
authors.initials: C
authors.lastname: Desplan
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology* / Q000254:growth & development; D002454:Cell Differentiation; D019070:Cell Lineage; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014795:Visual Pathways / Q000166:cytology
chemical_list: D029721:Drosophila Proteins; D014157:Transcription Factors