title: Pox neuro control of cell lineages that give rise to larval poly-innervated external sensory organs in Drosophila.
abstract: The Pox neuro (Poxn) gene of Drosophila plays a crucial role in the development of poly-innervated external sensory (p-es) organs. However, how Poxn exerts this role has remained elusive. In this study, we have analyzed the cell lineages of all larval p-es organs, namely of the kölbchen, papilla 6, and hair 3. Surprisingly, these lineages are distinct from any previously reported cell lineages of sensory organs. Unlike the well-established lineage of mono-innervated external sensory (m-es) organs and a previously proposed model of the p-es lineage, we demonstrate that all wild-type p-es lineages exhibit the following features: the secondary precursor, pIIa, gives rise to all three support cells-socket, shaft, and sheath, whereas the other secondary precursor, pIIb, is neuronal and gives rise to all neurons. We further show that in one of the p-es lineages, that of papilla 6, one cell undergoes apoptosis. By contrast in Poxn null mutants, all p-es lineages have a reduced number of cells and their pattern of cell divisions is changed to that of an m-es organ, with the exception of a lineage in a minority of mutant kölbchen that retains a second bipolar neuron. Indeed, the role of Poxn in p-es lineages is consistent with the specification of the developmental potential of secondary precursors and the regulation of cell division but not apoptosis.
authors.affiliation: Institute of Molecular Life Sciences, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
authors.forename: Yanrui
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Institute of Molecular Life Sciences, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Boll
authors.affiliation: Institute of Molecular Life Sciences, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland. Electronic address: markus.noll@imls.uzh.ch.
authors.forename: Markus
authors.initials: M
authors.lastname: Noll
mesh_terms: D000818:Animals; D019070:Cell Lineage / Q000502:physiology*; D003433:Crosses, Genetic; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology; D009474:Neurons / Q000166:cytology; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D017933:Peripheral Nervous System / Q000196:embryology*; D012679:Sense Organs / Q000166:cytology / Q000196:embryology*; D019076:Transgenes / Q000235:genetics
chemical_list: D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D051761:Paired Box Transcription Factors; C073863:Poxn protein, Drosophila
keywords: Apoptosis; Cell lineages; Drosophila; Larval p-es organs; Mitosis; PNS; Pox neuro