title: Functions of the segment polarity genes midline and H15 in Drosophila melanogaster neurogenesis.
abstract: The Drosophila melanogaster ventral nerve cord derives from neural progenitor cells called neuroblasts. Individual neuroblasts have unique gene expression profiles and give rise to distinct clones of neurons and glia. The specification of neuroblast identity provides a cell intrinsic mechanism which ultimately results in the generation of progeny which are different from each other. Segment polarity genes have a dual function in early neurogenesis: within distinct regions of the neuroectoderm, they are required both for neuroblast formation and for the specification of neuroblast identity. Previous studies of segment polarity gene function largely focused on neuroblasts that arise within the posterior part of the segment. Here we show that the segment polarity gene midline is required for neuroblast formation in the anterior-most part of the segment. Moreover, midline contributes to the specification of anterior neuroblast identity by negatively regulating the expression of Wingless and positively regulating the expression of Mirror. In the posterior-most part of the segment, midline and its paralog, H15, have partially redundant functions in the regulation of the NB marker Eagle. Hence, the segment polarity genes midline and H15 play an important role in the development of the ventral nerve cord in the anterior- and posterior-most part of the segment.
authors.affiliation: Medical Research Council Centre for Developmental Neurobiology, King's College London, 4th Floor New Hunt's House, Guy's Hospital Campus, London SE1 1UL, UK. marita.buescher@kcl.ac.uk
authors.forename: Marita
authors.initials: M
authors.lastname: Buescher
authors.forename: Murni
authors.initials: M
authors.lastname: Tio
authors.forename: Guy
authors.initials: G
authors.lastname: Tear
authors.forename: Paul M
authors.initials: PM
authors.lastname: Overton
authors.forename: William J
authors.initials: WJ
authors.lastname: Brook
authors.forename: William
authors.initials: W
authors.lastname: Chia
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002490:Central Nervous System / Q000196:embryology*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D038081:Organogenesis
chemical_list: D029721:Drosophila Proteins