title: Development of dendrite polarity in Drosophila neurons.
abstract: Drosophila neurons have dendrites that contain minus-end-out microtubules. This microtubule arrangement is different from that of cultured mammalian neurons, which have mixed polarity microtubules in dendrites.
  
  
  
  To determine whether Drosophila and mammalian dendrites have a common microtubule organization during development, we analyzed microtubule polarity in Drosophila dendritic arborization neuron dendrites at different stages of outgrowth from the cell body in vivo. As dendrites initially extended, they contained mixed polarity microtubules, like mammalian neurons developing in culture. Over a period of several days this mixed microtubule array gradually matured to a minus-end-out array. To determine whether features characteristic of dendrites were localized before uniform polarity was attained, we analyzed dendritic markers as dendrites developed. In all cases the markers took on their characteristic distribution while dendrites had mixed polarity. An axonal marker was also quite well excluded from dendrites throughout development, although this was perhaps more efficient in mature neurons. To confirm that dendrite character could be acquired in Drosophila while microtubules were mixed, we genetically disrupted uniform dendritic microtubule organization. Dendritic markers also localized correctly in this case.
  
  
  
  We conclude that developing Drosophila dendrites initially have mixed microtubule polarity. Over time they mature to uniform microtubule polarity. Dendrite identity is established before the mature microtubule arrangement is attained, during the period of mixed microtubule polarity.
authors.affiliation: Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Kargbo-Hill
authors.forename: Manpreet
authors.initials: M
authors.lastname: Parmar
authors.forename: Kyle W
authors.initials: KW
authors.lastname: Gheres
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Guignet
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Huang
authors.forename: F Rob
authors.initials: FR
authors.lastname: Jackson
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Rolls
mesh_terms: D000367:Age Factors; D000818:Animals; D030801:Animals, Genetically Modified; D009320:Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism; D016764:Cell Polarity / Q000235:genetics / Q000502:physiology*; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian; D036681:Fluorescence Recovery After Photobleaching; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D049452:Green Fluorescent Proteins; D007814:Larva; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D009474:Neurons / Q000166:cytology*; D034622:RNA Interference / Q000502:physiology; D012270:Ribosomes / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C467323:APC2 protein, Drosophila; D029721:Drosophila Proteins; D008869:Microtubule-Associated Proteins; D025521:Tumor Suppressor Proteins; D049452:Green Fluorescent Proteins; D009320:Atrial Natriuretic Factor