title: Chromator is required for proper microtubule spindle formation and mitosis in Drosophila.
abstract: The chromodomain protein, Chromator, has been shown to have multiple functions that include regulation of chromatin structure as well as coordination of muscle remodeling during metamorphosis depending on the developmental context. In this study we show that mitotic neuroblasts from brain squash preparations from larvae heteroallelic for the two Chromator loss-of-function alleles Chro(71) and Chro(612) have severe microtubule spindle and chromosome segregation defects that were associated with a reduction in brain size. The microtubule spindles formed were incomplete, unfocused, and/or without clear spindle poles and at anaphase chromosomes were lagging and scattered. Time-lapse analysis of mitosis in S2 cells depleted of Chromator by RNAi treatment suggested that the lagging and scattered chromosome phenotypes were caused by incomplete alignment of chromosomes at the metaphase plate, possibly due to a defective spindle-assembly checkpoint, as well as of frayed and unstable microtubule spindles during anaphase. Expression of full-length Chromator transgenes under endogenous promoter control restored both microtubule spindle morphology as well as brain size strongly indicating that the observed mutant defects were directly attributable to lack of Chromator function.
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology, 3156 Molecular Biology Building, Iowa State University, Ames, IA 50011, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Ding
authors.forename: Changfu
authors.initials: C
authors.lastname: Yao
authors.forename: Mariana
authors.initials: M
authors.lastname: Lince-Faria
authors.forename: Uttama
authors.initials: U
authors.lastname: Rath
authors.forename: Weili
authors.initials: W
authors.lastname: Cai
authors.forename: Helder
authors.initials: H
authors.lastname: Maiato
authors.forename: Jack
authors.initials: J
authors.lastname: Girton
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Johansen
authors.forename: Jørgen
authors.initials: J
authors.lastname: Johansen
mesh_terms: D000818:Animals; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D007150:Immunohistochemistry; D007814:Larva / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D034521:Nuclear Matrix-Associated Proteins / Q000235:genetics* / Q000378:metabolism*; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D008941:Spindle Apparatus / Q000502:physiology*
chemical_list: C498868:Chro protein, Drosophila; D029721:Drosophila Proteins; D034521:Nuclear Matrix-Associated Proteins