Skip to main content
Article thumbnail
Location of Repository

Investigating the cellular and molecular mechanisms involved in establishing and maintaining centrosome asymmetry in Drosophila neuroblasts

By Anjana Ramdas Nair


Centrosome asymmetry has been implicated in stem cell fate maintenance in both flies and vertebrates. Drosophila neuroblasts, the neural precursors of the fly’s central nervous system, contain molecularly and physically asymmetric centrosomes. For instance, the apical daughter centrosome maintains a stable microtubule organizing center (MTOC) activity and remains tethered to the apical cortex throughout the cell cycle. The basal mother centrosome, however, loses MTOC activity and only regains it during prophase. This centrosome asymmetry is important for centrosome positioning, spindle orientation and centrosome segregation during asymmetric cell division. \ud In a gene candidate approach, we identified Bld10, fly ortholog of Cep135 and the uncharacterized gene CG7337, the fly ortholog of WDR62, as a regulator of centrosome asymmetry during interphase. In bld10 mutant neuroblasts the mother centrosome does not downregulate MTOC activity resulting in two mature active centrosomes. As a consequence of perturbed centrosome asymmetry, we observed spindle misalignment during metaphase and centrosome missegregation. In contrast, we were able to show that in CG7337/wdr62 mutant neuroblasts both centrosomes lose MTOC activity, resulting in interphase neuroblasts containing two untethered centrioles. Moreover, cold treatment of wdr62 mutant neuroblasts displayed microtubule instability while over expression of Wdr62 had hyper stabilized microtubules. We also observed decrease in Polo levels on the apical centrosome in mutant neuroblasts. Wdr62 localizes to the microtubules during the cell cycle. Taken together, we concluded that Wdr62 plays an important role in stabilizing microtubules, which are necessary for recruitment of Polo, and hence, maintains centrosome asymmetry. In addition, wdr62 mutants display cell cycle delay and decrease in brain size. \ud To gain further insight into the neuroblast centrosome cycle and centrosome asymmetry establishment, we used 3D-SIM (Structured Illumination Microscopy). We observed that centriole duplication begins soon after centriole separation and molecular markers involved in establishing centrosome asymmetry have a very precise segregation pattern based on the age of the centrioles. Using 3D-SIM, we are able to define the time points of the occurrence of these event

Year: 2015
DOI identifier: 10.5451/unibas-006624633
OAI identifier:
Provided by: edoc

Suggested articles


  1. (2007). [Mechanisms of asymmetric stem cell division in the Drosophila male germ line].
  2. (1995). 3-Dimensional Structural Characterization of Centrosomes From Early Drosophila Embryos.
  3. (2012). 3D-structured illumination microscopy provides novel insight into architecture of human centrosomes.
  4. (2008). A genome-wide RNAi screen to dissect centriole duplication and centrosome maturation in Drosophila.
  5. (1995). A Molecular Marker for Centriole Maturation in the Mammalian-Cell Cycle.
  6. (2014). A molecular mechanism of mitotic centrosome assembly in Drosophila.
  7. (2000). A new function for the gamma-tubulin ring complex as a microtubule minus-end cap.
  8. (2000). A protein complex containing Inscuteable and the Galpha-binding protein Pins orients asymmetric cell divisions in Drosophila.
  9. (2007). A role for a novel centrosome cycle in asymmetric cell division.
  10. (2011). An ana2/ctp/mud complex regulates spindle orientation in Drosophila neuroblasts.
  11. (2010). An overview of Cdk1-controlled targets and processes.
  12. (2009). Ana3 is a conserved protein required for the structural integrity of centrioles and basal bodies.
  13. (1996). Antibody microinjection reveals an essential role for human polo-like kinase 1 (Plk1) in the functional maturation of mitotic centrosomes.
  14. (2012). Assembly and Persistence of Primary Cilia in Dividing Drosophila Spermatocytes.
  15. (2011). Assessing the localization of centrosomal proteins by PALM/STORM nanoscopy.
  16. (2009). Asymmetric centrosome inheritance maintains neural progenitors in the neocortex.
  17. (2001). Aurora-A kinase is required for centrosome maturation in Caenorhabditis elegans.
  18. (2005). Basal body duplication and maintenance require one member of the Tetrahymena thermophila centrin gene family.
  19. (2007). Bld10p constitutes the cartwheelspoke tip and stabilizes the 9-fold symmetry of the centriole.
  20. (2013). Caenorhabditis elegans centriolar protein SAS-6 forms a spiral that is consistent with imparting a ninefold symmetry.
  21. (2013). CCDC41 is required for ciliary vesicle docking to the mother centriole.
  22. (2006). Cell biology - A licence for duplication.
  23. (1995). Cell-Cycle Regulation of the Activity and Subcellular-Localization of Plk1, a Human Protein-Kinase Implicated in Mitotic Spindle Function.
  24. (2005). Centrin deficiency in Paramecium affects the geometry of basal-body duplication.
  25. (2004). Centriolar SAS-5 is required for centrosome duplication in C-elegans.
  26. (2006). Centriole assembly in C. elegans.
  27. (2006). Centriole assembly in Caenorhabditis elegans.
  28. (1981). Centriole Cycle in Chinese-Hamster Ovary Cells as Determined by Whole-Mount Electron-Microscopy.
  29. (2013). Centriole distal appendages promote membrane docking, leading to cilia initiation.
  30. (2010). Centrioles Regulate Centrosome Size by Controlling the Rate of Cnn Incorporation into the PCM. Current Biology,
  31. (1994). Centrosome Assembly inVitro - Role of Gamma-Tubulin Recruitment in Xenopus Sperm Aster Formation.
  32. (2009). Centrosome function in cancer: guilty or innocent? Trends in
  33. (2004). Centrosome maturation and duplication in C. elegans require the coiled-coil protein SPD-2. Developmental Cell,
  34. (2003). Centrosome number is controlled by a centrosome-intrinsic block to reduplication.
  35. (1992). Centrosome Organization and Centriole Architecture - Their Sensitivity to Divalent-Cations.
  36. (1998). Centrosomes and microtubule organisation during Drosophila development.
  37. (2005). Centrosomes in cellular regulation.
  38. (1989). Centrosomes, and Not Nuclei, Initiate Pole Cell-Formation in Drosophila Embryos.
  39. (2013). CEP120 interacts with CPAP and positively regulates centriole elongation.
  40. (2010). Cep120 is asymmetrically localized to the daughter centriole and is essential for centriole assembly.
  41. (2013). CEP162 is an axoneme-recognition protein promoting ciliary transition zone assembly at the cilia base.
  42. (2005). Chromosome segregation and aneuploidy series: Centrosome control of the cell.
  43. (2010). Cnn Dynamics Drive Centrosome Size Asymmetry Ito Ensure Daughter Centriole Retention in Drosophila Neuroblasts. Current Biology,
  44. (1990). Components of the Yeast Spindle and Spindle Pole Body.
  45. (2001). Control of stem cell self-renewal in Drosophila spermatogenesis by JAK-STAT signaling.
  46. (2006). Controlling centrosome number: licenses and blocks.
  47. (2013). CP110 exhibits novel regulatory activities during centriole assembly in Drosophila.
  48. (2009). CPAP is a cell-cycle regulated protein that controls centriole length.
  49. (2013). CRISPR/Cas9-mediated genome engineering and the promise of designer flies on demand.
  50. (2013). Crystal structures of the CPAP/STIL complex reveal its role in centriole assembly and human microcephaly.
  51. (1999). Cyclin-dependent kinase 2 (Cdk2) is required for centrosome duplication in mammalian cells.
  52. (1999). Cyclin-dependent kinase control of centrosome duplication.
  53. (2012). Dgp71WD is required for the assembly of the acentrosomal Meiosis I spindle, and is not a general targeting factor for the γ-TuRC.
  54. (2015). Different Drosophila cell types exhibit differences in mitotic centrosome assembly dynamics.
  55. (2010). Drosophila Ana2 is a conserved centriole duplication factor.
  56. (2002). Drosophila Aurora A kinase is required to localize D-TACC to centrosomes and to regulate astral microtubules.
  57. (2009). Drosophila bld10 is a centriolar protein that regulates centriole, basal body, and motile cilium assembly. Molecular Biology of the Cell,
  58. (2012). Drosophila Cep135/Bld10 maintains proper centriole structure but is dispensable for cartwheel formation.
  59. (2011). Drosophila neuroblasts retain the daughter centrosome.
  60. (2012). Drosophila neuroblasts: a model for stem cell biology.
  61. (2014). Drosophila pericentrin requires interaction with calmodulin for its function at centrosomes and neuronal basal bodies but not at sperm basal bodies.
  62. (2006). Drosophila Pins-binding protein Mud regulates spindle-polarity coupling and centrosome organization.
  63. (2007). Drosophila Spd-2 recruits PCM to the sperm centriole, but is dispensable for centriole duplication.
  64. (2014). Ecdysone and mediator change energy metabolism to terminate proliferation in Drosophila neural stem cells.
  65. (2003). Elucidation of basal body and centriole functions in Chlamydomonas reinhardtii.
  66. (2004). Formation and remodeling of epithelial polarity.
  67. (2007). From stem cell to embryo without centrioles.
  68. (1990). Gamma-Tubulin Is a Component of the Spindle Pole Body That Is Essential for Microtubule Function in AspergillusNidulans.
  69. (2000). gammatubulin complexes and their role in microtubule nucleation.
  70. (2002). Genes associated with centrosome amplification in development and progression of breast cancer.
  71. (2014). Highly specific and efficient CRISPR/Cas9-catalyzed homologydirected repair in Drosophila. Genetics,
  72. (2013). Human microcephaly protein CEP135 binds to hSAS-6 and CPAP, and is required for centriole assembly.
  73. (1999). In vivo localisation of the mitotic POLO kinase shows a highly dynamic association with the mitotic apparatus during early embryogenesis in Drosophila.
  74. (1994). In-Vitro Reconstitution of Centrosome Assembly and Function - the Central Role of Gamma-Tubulin.
  75. (1998). Interactions between mgr, asp, and polo: asp function modulated by polo and needed to maintain the poles of monopolar and bipolar spindles.
  76. (2007). Katanin regulates dynamics of microtubules and biogenesis of motile cilia.
  77. (2008). Linking cell cycle to asymmetric division: Aurora-A phosphorylates the par complex to regulate Numb localization.
  78. (2008). Lis1/dynactin regulates metaphase spindle orientation in Drosophila neuroblasts.
  79. (2006). Mechanism limiting centrosome duplication to once per cell cycle.
  80. (2004). Mechanisms and molecules of the mitotic spindle.
  81. (2008). Mechanisms of procentriole formation.
  82. (2013). Mechanisms of spindle positioning: cortical force generators in the limelight.
  83. (2014). Microcephaly disease gene Wdr62 regulates mitotic progression of embryonic neural stem cells and brain size.
  84. (1995). Microtubule Nucleation by Gamma-Tubulin-Containing Rings in the Centrosome.
  85. (2005). Microtubule-induced Pins/G alpha i cortical polarity in Drosophila neuroblasts.
  86. (1989). Mitosis in Drosophila Development.
  87. (1993). Molecular components of the centrosome.
  88. (2005). Molecular control of cell polarity and asymmetric cell division in Drosophila neuroblasts.
  89. (2005). Molecular links between centrosome and midbody.
  90. (2003). Morphologically distinct microtubule ends in the mitotic centrosome of Caenorhabditis elegans.
  91. (2009). Neural stem cell transcriptional networks highlight genes essential for nervous system development.
  92. (2010). Notch regulates the switch from symmetric to asymmetric neural stem cell division in the Drosophila optic lobe.
  93. (2013). Novel Pericentrin structures orchestrate the PCM in rapidly dividing embryos.
  94. (1995). Nucleation of Microtubule Assembly by a Gamma-Tubulin-Containing Ring Complex.
  95. (2013). NuMA phosphorylation by CDK1 couples mitotic progression with cortical dynein function.
  96. (2009). NuMA-related LIN-5, ASPM-1, calmodulin and dynein promote meiotic spindle rotation independently of cortical LIN-5/GPR/G alpha.
  97. (2015). Opposing roles for JNK and Aurora A in regulating the association of WDR62 with spindle microtubules.
  98. (2013). Optimized gene editing technology for Drosophila melanogaster using germ line-specific
  99. (2013). Overexpression of WDR62 is associated with centrosome amplification in human ovarian cancer.
  100. (1998). Pericentrin and gamma-tubulin form a protein complex and are organized into a novel lattice at the centrosome.
  101. (1994). Pericentrin, a highly conserved centrosome protein involved in microtubule organization.
  102. (2011). Phosphorylation at serine 482 affects stability of NF90 and its functional role in mitosis.
  103. (2007). Plk4-induced centriole biogenesis in human cells.
  104. (2014). PLP forms novel centriole satellites and is critical for embryonic development.
  105. (2013). PLP inhibits the activity of interphase centrosomes to ensure their proper segregation in stem cells.
  106. (2005). Polo kinase and progression through M phase in Drosophila: a perspective from the spindle poles.
  107. (1998). Polo-like kinases: a team that plays throughout mitosis.
  108. (1988). Polo, a Mitotic Mutant of Drosophila Displaying Abnormal Spindle Poles.
  109. (2009). Primary microcephaly: do all roads lead to Rome? Trends in
  110. (2006). Prospero acts as a binary switch between self-renewal and differentiation in Drosophila neural stem cells.
  111. (2001). Protein localization during asymmetric cell division.
  112. (2011). Regulating the balance between symmetric and asymmetric stem cell division in the developing brain.
  113. (2009). Regulation of primary cilia formation by ceramide.
  114. (2007). Regulation of spindle orientation and neural stem cell fate in the Drosophila optic lobe.
  115. (2015). required for efficient centriole assembly in flies.
  116. (2001). Requirement of Hsp90 for centrosomal function reflects its regulation of Polo kinase stability. Embo Journal,
  117. (2003). SAS-4 is a Celegans centriolar protein that controls centrosome size.
  118. (2003). SAS-4 is essential for centrosome duplication in C-elegans and is recruited to daughter centrioles once per cell cycle.
  119. (2005). SAS-6 defines a protein family required for centrosome duplication in C-elegans and in human cells.
  120. (2011). SAS-6 oligomerization: the key to the centriole?
  121. (2014). Small organelle, big responsibility: the role of centrosomes in development and disease.
  122. (1988). Spatial and Temporal Patterns of Neurogenesis in the Central Nervous-System of Drosophila-Melanogaster.
  123. (2011). Spindle positioning in human cells relies on proper centriole formation and on the microcephaly proteins CPAP and STIL.
  124. (2012). STED Microscopy with Optimized Labeling Density Reveals 9-Fold Arrangement of a Centriole Protein.
  125. (2014). Stem cell decisions: a twist of fate or a niche market?
  126. (2001). Stem cell selfrenewal specified by JAK-STAT activation in response to a support cell cue.
  127. (2012). Structured illumination of the interface between centriole and pericentriolar material.
  128. (2012). Subdiffraction imaging of centrosomes reveals higher-order organizational features of pericentriolar material.
  129. (2012). Subdiffraction-resolution fluorescence microscopy reveals a domain of the centrosome critical for pericentriolar material organization.
  130. (2008). Temporal transcription factors and their targets schedule the end of neural proliferation in Drosophila.
  131. (2004). The budding yeast spindle pole body: Structure, duplication, and function.
  132. (2001). The C. elegans zyg-1 gene encodes a regulator of centrosome duplication with distinct maternal and paternal roles in the embryo.
  133. (2006). The Caenorhabditis elegans centrosomal protein SPD-2 is required for both pericentriolar material recruitment and centriole duplication (vol 14, pg 863,
  134. (2014). The centriolar protein Bld10/Cep135 is required to establish centrosome asymmetry in Drosophila neuroblasts.
  135. (2015). The Centrosome and Its Duplication Cycle.
  136. (2011). The centrosome cycle: Centriole biogenesis, duplication and inherent asymmetries.
  137. (2006). The Drosophila NuMA homolog mud regulates spindle orientation in asymmetric cell division.
  138. (2015). The Drosophila Pericentrin-like-protein (PLP) cooperates with Cnn to maintain the integrity of the outer PCM.
  139. (1996). The family of polo-like kinases.
  140. (2007). The inhibition of polo kinase by matrimony maintains G2 arrest in the meiotic cell cycle.
  141. (2010). The interphase microtubule aster is a determinant of asymmetric division orientation in Drosophila neuroblasts.
  142. (2004). The mechanism of spindle assembly: functions of Ran and its target TPX2.
  143. (2006). The NuMA-related Mud protein binds Pins and regulates spindle orientation in Drosophila neuroblasts.
  144. (2000). The respective contributions of the mother and daughter centrioles to centrosome activity and behavior in vertebrate cells.
  145. (2003). Three-dimensional organization of basal bodies from wild-type and delta-tubulin deletion strains of Chlamydomonas reinhardtii.
  146. (2012). Towards a molecular architecture of centriole assembly.
  147. (2010). WDR62 is associated with the spindle pole and is mutated in human microcephaly.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.